Expandable devices, rail systems, and motorized devices

ABSTRACT

Provided herein are expandable devices, rail systems, and motorized devices. In one embodiment, an expandable device comprises an expandable sac having a tool housed therein. The expandable device is optionally configured for operation while inside a body cavity. The expandable device optionally comprises at least one rail in the sac, and at least one railed device coupled to the rail for movement there on. Movement of the railed device on the rail is provided by, for example, a motor such as an electromagnetic motor or an inch-worm type motor. Expandable devices can be used, for example, to perform minimally invasive medical procedures requiring access to a body cavity. Expandable devices can also be used, for example, to provide safe and stable transport of instruments to the body cavity.

CROSS-REFERENCE

This application is a continuation of U.S. application Ser. No.15/140,176 filed on 27 Apr. 2016, which is a continuation of U.S.application Ser. No. 13/877,660 filed on 3 Apr. 2013, which is a 371national stage entry of PCT/US11/54829 filed on 4 Oct. 2011, whichclaims the benefit of U.S. provisional application Ser. No. 61/404,395filed on 4 Oct. 2010, which are each incorporated by reference in theirentirety.

TECHNICAL FIELD

The present invention relates to expandable devices, rail systems, andmotorized devices.

BACKGROUND

Invasive surgical procedures are often used to address various medicalconditions. When possible, minimally invasive procedures such aslaparoscopy are preferred. However, known minimally invasivetechnologies such as laparoscopy are limited in scope and complexity duein part to 1) mobility restrictions resulting from using rigid toolsinserted through incisions, 2) limited visual feedback and otherdrawbacks described in the medical literature [The pitfalls oflaparoscopic surgery: challenges for robotics and telerobotic surgery.Ballantyne GH. Surg Laparosc Endosc Percutan Tech. 2002 February;12(1):1-5].

Technical progress in the field has resulted in more flexibleinstruments that are less rigid and possess greater degrees of freedomfor positioning the tiny tools located at the tip of the flexible scopesoften shaped like snakes and having several internal conduits or portsthrough which lighting sources, irrigation or suctioning and otherfunctional instrumentation can be threaded along the long axis of thescope. Nevertheless, there are still significant limitations in the useof these instruments as described in the literature [Karimyan et al.“Navigation systems and platforms in natural orifice translumenalendoscopic surgery (NOTES)”. Int J Surg. 2009 August; 7(4):297-304. Epub2009 May 27; Mintz et al. “Hybrid natural orifice translumenal surgery(NOTES) sleeve gastrectomy: a feasibility study using an animal model”.Surg Endosc. 2008 August; 22(8):1798-802. Epub 2008 Apr. 25].

Continued advances in the field have imparted additional functionalityto the flexible scoped instruments. However, among the still extantlimitations, these instruments must be pushed through the body cavitiesby the operator without adequate visual or tactile feedback from thebody organs and tissues, resulting in instances of puncturing throughorgan walls and other compilations. Hence, instruments have been devisedthat possess forward propulsion, the ability to advance forward withoutbeing pushed [e.g. Long, G: U.S. Pat. Nos. 7,226,410, 7,351,202; Hillel,J et al. U.S. Pat. No. 6,764,441; Grundfest at al. U.S. Pat. No.5,337,732].

Another advance in the field is to employ several different devices,including micro robots, that function in cooperation with each other[Forgione et al., Surg Oncol. 2009 June; 18(2):121-9. Epub 2009 Jan. 14.“In vivo microrobots for natural orifice transluminal surgery. Currentstatus and future perspectives; Michelini & Razzolini; Co-operativeminimally invasive robotic surgery, Industrial Robot: Vol 35, No. 4,2008, 347-360.]. These robotic devices must still be propelled andguided by mechanical capabilities or by external means within the bodycavities or lumens and must work alone or cooperatively within bodyspaces in which it is difficult to maneuver, and these robotic devicesmust be retrieved without undue burden on the patient or surgeon.Configured to perform specific tasks heretofore accomplished by manuallydelivered instruments, these robotic devices need appropriate space,protection from the internal body environments (designed to self-protectfrom foreign organisms or tissue), and energy means plus structuralcomponents to be able to maneuver inside the body—all this, is anunnecessary burden, since they are designed to perform a specifictask(s) e.g., cutting, retracting, ablating, cauterizing, sewing,stapling, imaging and the like.

US 2009/0076536 (Rentschler et al.) describes a medical devicepositioning device comprising a rail supported by four legs in aswing-set-like structure. A medical device is moveably attached to therail such that the device can move back and forth along the rail. Amongother technical features, '536 does not teach an expandable saccomprising a rail, an expandable sac comprising a second inner sac inits lumen, an expandable sac comprising an diagnostic or therapeuticdevice in its lumen, or a malleable sac.

U.S. Pat. No. 6,605,037 (Moll et al.) describes an inflatable retractiondevice for retracting an organ inside a body to gain access to anadjacent tissue. The device comprises a first envelope enclosing a firstinflatable chamber. Inside the first inflatable: chamber is thenon-pressurized chamber, which is maintained in an expanded condition bythe second inflatable chamber. Among other technical features, '037 doesnot teach an expandable sac comprising a rail, an expandable saccomprising an diagnostic or therapeutic device in its lumen, or amalleable sac.

There exists a need to fill significant gaps in the functionality ofthese various devices, taken alone or in unison. What is needed in theart are improved surgical devices for performing minimally invasivediagnostic or therapeutic procedures.

Among other advantages, the present invention, in one embodiment, ispresented as an innovative expandable device capable of performing avast number of diagnostic and therapeutic procedures.

SUMMARY OF THE INVENTION

The invention provides novel expandable devices, motorized devices, andrail systems for mobile devices.

A first aspect of the invention provides an expandable device forperforming diagnostic and/or therapeutic procedures. An expandabledevice of the present invention comprises at least one expandable sac(‘sac’) and a tool housed therein, and is configured for operation whileinside a body cavity. The sac is configured such that it can bemanipulated from a collapsed state to an expanded state. An explamplarysac is an inflatable sac. An expandable device of the present inventionfurther comprises one or more of following technical features:

-   -   a. a rail system;    -   b. a robotic tool in the lumen of a sac;    -   c. a ported sac with a diagnostic or therapeutic (d/t) tool in        the lumen of the sac;    -   d. a multilayer configuration; and    -   e. a malleable sac.

The invention contemplates an expandable device having any 1, 2, 3, 4,or all 5 of the above-listed technical features.

In one embodiment, the expandable device has a rail system comprising atleast one rail in the lumen of the sac, and at least one railed devicecoupled to the rail for movement there on. Movement of the raileddevice(s) on the rail is provided by, for example, a motor such as anelectromagnetic motor or an inch-worm type motor. Optionally, theexpandable device comprises one or more robots and/or one or more d/ttools as railed devices. Optionally, the sac is tethered to the raileddevice such that the sac, or segment thereof, can be positioned bymoving the railed device on the rail. Such expandable devices with arail system are optionally provided with: a ported sac, a multilayeredconfiguration, a malleable sac, or any combination thereof.

In one embodiment, the expandable device has a robotic tool (‘robot’) inthe lumen of a sac. Optionally, the robot is a microrobot. Optionallythe robot is a d/t tool. Optionally, the robot is a housekeeping robot.Optionally, the robot is a fragmented tool or a foldable tool. When therobotic tool is a d/t device, the expansion of the sac optionallyprovides a working environment for the d/t device. Optionally, theexpandable device comprises a plurality of robots. Optionally, theexpandable device comprises a rail system and at least one of the robotsis a railed device and at least one of the robots is a non-raileddevice. Such expandable devices comprising a robotic tool are optionallyprovided with: a ported sac and at least one robotic d/t tool, amultilayered configuration, a malleable sac, or any combination thereof.

In one embodiment, the expandable device is a ported sac with adiagnostic or therapeutic (d/t) tool in the lumen of the sac. Such anexpandable device comprises a sac with a port in a wall of the sac. Theport can is sized, for example, to allow passage of the tool therethrough and/or access to a target site external to the sac. Optionally,the port is a valve. Optionally, the d/t tool is a robot. Optionally,the expandable device comprises a rail system and the d/t tool is arailed device. Such expandable devices comprising a ported sac areoptionally provided with: a multilayered configuration, a malleable sac,or a combination thereof.

In one embodiment, the expandable device is a multilayer device. Amultilayer device of the invention comprises an outer sac and at leastone inner sac, wherein the at least one inner sac is in the lumen of theouter sac. Optionally, the inner sac is configured to be filled with afluid to impart volume to the outer sac. Optionally, the device isconfigured to be filled with a fluid between the walls of the inner andouter sacs, for example, a lubricating fluid. Optionally, one or more ofthe inner and outer sacs comprises a tool (e.g. camera, lighting source,and/or robot), for example, in the lumen thereof. Optionally, themultilayer device comprises a first inner sac configured to be filledwith a fluid to impart volume to the outer sac, and a second inner saccomprising a tool, for example, in the lumen thereof. Such multilayerdevices are optionally provided with: a rail system, a malleable sac, ora combination thereof.

In one embodiment, the expandable device comprises a malleable sac.Optionally, the sac is configured for expansion by fluid pressure(‘inflation’). For example, the sac is configured for inflation up beingdirectly filled with a fluid (e.g. by access tube) or comprises an innersac which is configured to be filled with a fluid (e.g. by access tube).Optionally, the wall of the malleable sac is made from any of: apolymer, a metal, or a dispersion of particles in a medium, a dynamicplastic, or a polymer malleable at a physiologically acceptabletemperature. Optionally, the malleable sac is configured to remainexpanded in the absence of luminal pressure. Optionally, the malleablesac is configured to contour against a surface (e.g. organ) uponexpansion. Such expandable devices with a malleable sac are optionallyprovided with any of: a rail system, a robotic device, a ported sac, orany combination thereof.

Examplary expandable devices of the present invention are configuredsuch that they can be inserted into a body cavity through a smallpassageway (e.g. incision or orifice) and expanded to provide a workenvironment for conducting a medical procedure in the body cavity.

A second aspect of the invention provides a mobile (motorized) device.The mobile device comprises an electromagnetic motor having three cars,wherein: a) each of the three cars comprises an electromagnet; b) eachof the three electromagnets is independently operable; and c) the threeelectromagnets are arranged in a substantially collinear configurationsuch that a pole on each car is oriented for interaction with the poleof another car. In one embodiment, the three cars include a lead car, anintermediate car, and a trail car. The cars can be configured to move inan inchworm manner. Optionally, the mobile device is provided with thefollowing configuration: the weight of the intermediate car is less thanthe lead car and less than the trail car; the weight of the lead car isless than the combined weight of the intermediate and trail car; and theweight of the trail car is less than the combined weight of theintermediate and lead car. Optionally, the mobile device furthercomprises a rail linking the cars for movement along a path. Optionally,the mobile device comprises a distance limiter for restraining the carsfrom moving further than a maximum distance from each other (e.g. themaximum distance of electromagnetic interaction between the cars).

Such a mobile device is optionally provided as a railed device in anexpandable device of the invention. However, such a mobile device isalternatively used without expandable devices of the present inventionwhere the mobile device can be coupled to any type of device formovement of the device (e.g. robot, microrobot, or imaging device).

A third aspect of the present invention provides a rail system. In oneembodiment, the rail system comprises an inflatable rail for movement ofa railed device. An inflatable rail of the invention comprises a conduitmade from a flexible material, wherein: the conduit comprises an inletfor filling and inflating the conduit with a fluid; the conduit isconfigured to be turgid when inflated and flexible or flaccid when notinflated; and when turgid, the inflatable rail provides a support and aguide to the railed device for movement on the inflatable rail.Optionally, the rail comprises a fork in the conduit, wherein the forkbranches a single conduit into a plurality of conduits, wherein each ofthe plurality of conduits can support a railed device when turgid.Optionally, the fork comprises a control circuit configured todifferentially control the flow of fluid from the single conduit intothe plurality of conduits. Optionally, the control circuit is a fluidicamplifier. Optionally, the railed device is a robot (e.g. microrobot) orcomprises a d/t tool. Optionally, the railed device comprises aninchworm type motor or an electromagnetic motor.

Such an inflatable rail is optionally provided as a rail in anexpandable device of the invention. However, such an inflatable rail isalternatively used without expandable devices of the present inventionwhere the inflatable rail can be coupled with any type of railed device(e.g. robot, microrobot, or imaging device).

Any of the technical features listed above may be provided alone or incombination with any other to provide a device of the present invention.Accordingly, the invention also contemplates devices having anycombination of the technical features listed above.

The invention also contemplates devices having any combination of thetechnical features listed above with any other embodiment taught herein(unless the combination of technical features is inconsistent with theexpress teachings of the embodiment).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a device of the present invention comprising raileddevices.

FIG. 2A and FIG. 2B depict a multilayered device of the presentinvention comprising ports.

FIG. 3A and FIG. 3B depict a device of the present invention.

FIG. 4 depicts a multilayered device of the present invention comprisingan expandable framework.

FIG. 5A and FIG. 5B depict a multilayered device of the presentinvention comprising a tool.

FIG. 6A through FIG. 6G depict an inchworm type electromagnetic motoruseful in a device of the present invention.

FIG. 7 depicts a motorized railed device coupled to rail, useful in adevice of the present invention.

FIG. 8A depicts an expandable device of the invention. FIG. 8B throughFIG. 8D depict parts thereof.

FIG. 9A through FIG. 9E depict embodiments of an expandable device ofthe invention.

FIG. 10A and FIG. 10B depict an expandable device of the invention.

FIG. 11 depicts a robot useful in an expandable device of the invention.

FIG. 12A depicts an expandable device of the invention. FIG. 12B throughFIG. 12F depict parts thereof.

FIG. 13A and FIG. 13B depict a pleated expandable sac.

FIG. 14A through FIG. 14C depict motorized devices tethered to a sacwall.

FIG. 15 depicts a fragmented tool.

DETAILED DESCRIPTION OF THE INVENTION

As used here, the following definitions and abbreviations apply.

“Examplary” (or “e.g.” or “by example”) means a non-limiting example.

“Expandable device” means a device comprising an expandable sac and atleast one tool. In one embodiment, an expandable device is a multilayerdevice.

“Multilayer device” means en expandable sac comprising an outerexpandable sac and an inner expandable sac in the lumen of the outerexpandable sac.

“Substantially non-elastic” means the sac is substantially less elasticthan a latex balloon. The elasticity of latex causes an inflated latexballoon to immediately contract to its original state after luminalpressure has been released. A malleable sac of the present invention issubstantially non-elastic.

“Physiologically acceptable temperature” means a temperature at which anexpandable sac may be expanded in a body cavity without causingsubstantial ablation of cells in the body cavity. Examplary devices ofthe present invention comprise an expandable sac that is malleable at aphysiologically acceptable temperature. In one embodiment, thephysiologically acceptable temperature is any of: less than about 50°C., less than about 45° C., less than about 40° C., or about 35 to about37° C.

Expandable Sacs

In one embodiment, the invention provides an expandable devicecomprising at least one expandable sac and a tool. The expandable saccan be any envelope defining a lumen and having at least two states: acollapsed state and an expanded state. In one embodiment, the sac isconfigured to be inserted into a body cavity in a collapsed state inwhich the sac has a minimal (or reduced) volume and/or cross sectionalarea, and then expanded in the body cavity to a state that has greatervolume and/or cross-sectional area.

In one embodiment, the expandable sac is any of: a malleable envelope, aflexible envelope (e.g. membrane or balloon), or a pleated envelope.

In one embodiment, the expandable sac is made from a material that isany of: flexible and substantially non-elastic, elastic, viscoelastic,viscoplastic, compliant, flexible and non-compliant, malleable, ornon-malleable. The skilled artisan will recognize that such sacs are notlimited to any particular material. There are many known materials thatcan be configured with one or more of such physical properties.

The expandable sac can be made from any material, for example, a metal,a polymer, or a dispersion of particles in a medium. Examplary metalsinclude malleable metals such as gold, platinum, palladium, and silver.Examplary polymers include semi-crystalline and amorphous polymers.Examplary polymers include any of the following types: polyolefins (e.g.Low density polyethylene (LDPE), high density polyethylene (HDPE), orpolypropylene (PP)), styrenics, vinyls (e.g. PVC), acrylics (e.g.polymethyl methacrylate), fluoropolymers (e.g. PTFE, CTFE), polyesters(e.g. PET), polyamides (Nylons), polyimides, polyethers, and sulfurcontaining polymers.

In one embodiment, the expandable sac comprises pleats. Such a pleatedenvelope comprises segments (sac wall portions) connected by flexiblepleats or preformed fold lines. The segments are optionally rigid orflexible. If the segments are flexible, the pleats can have greaterflexibility than the flexible segments.

In one embodiment, the expandable sac is a dip molded or blow moldedenvelope. Examples of such are well known in the art. A blow moldedenvelope can be provided, for example, by a) beginning with a plasticresin hot tube (a parison) or pre-form; b) the parison is placed withina split mold with a hollow cavity; c) the mold sides are then clampedtogether, pinching and sealing the parison tube; d) air is blown intothe tube, which expands the hot resin wall into the shape of the cavity;e) the mold is cooled with water solidifying the resin into the desiredshape.

In one embodiment, the expandable sac is sized to fit in a body cavityor body lumen (‘body cavity’) of a patient (e.g. human) while expanded.Examples of patients include a human, a ruminant, a canine, and anelephant. Examples of body cavities in which the sac can be configuredfor placement include the abdomen, colon, large intestine, smallintestine, GI tract, vagina, uterus, fallopian tubes, thoracic cavity,pleural cavity, sinuses, urethra, ureters (e.g. a cavity of a human).The sac can also be sized for small lumens or vessels filled with afluid (e.g. blood or lymphatic vessels).

In one embodiment, the expandable sac comprises at least one tool in itslumen. Optionally, the sac is configured such that expansion of the sacprovides one or more of: a work environment for the tool at a targetsite, retraction of organs or other tissue from the target site, andstabilization of the sac against the walls of a body cavity.

In one embodiment, the sac is configured to support a rail and a raileddevice. In such a device, the sac is configured such that, at least uponexpansion, a work environment is provided that railed devices can movewithin.

In one embodiment, the sac comprises at least one port.

In one embodiment, the sac comprises an access tube.

In one embodiment, the sac comprises a port and an access tube.

In one embodiment, the device is a multilayer device comprising an outersac and at least one inner sac in the lumen of the outer sac.Optionally, one or more of the outer and inner sacs comprises an accesstube. Optionally, one or more of the outer and inner sacs comprises aport.

In one embodiment, the sac is transparent. Such a sac is especiallyuseful for allowing imaging of a body lumen by a camera mounted in thelumen of the sac. Examples of materials useful for creating transparentsacs include PVC and nylon. Other transparent materials that can beconfigures as expandable sacs are well known in the art.

In one embodiment, the sac comprises sensors (e.g. motion sensors), forexample, embedded in the sac wall.

In one embodiment, the sac is an outer sac comprising traction-impartingprotrusions or filaments extending from the exterior of the sac.

In one embodiment, an expandable sac is configured for expansion byinflation or other means for providing luminal pressure.

In one embodiment, the sac is made from a material that is expandable,durable, and of biocompatible material. Examples of such materials arewell known in the art.

Malleable Sacs

In one embodiment, the sac is malleable and/or ductile (‘malleablesac’). Malleability is a material's ability to deform under compressivestress. Ductility is a material's ability to deform under tensilestress. Useful malleable sacs according to the present invention arethose which are deformable and substantially non-elastic. In oneembodiment, a malleable sac is both malleable and ductile. Any portion(surface area) of the envelope can be malleable, for example, the entireenvelope, a majority of the envelope, or segments of the envelope.

The malleable sac can be made from any malleable material. In oneembodiment, the malleable sac is made from a material selected from: athermoplastic resin, a viscoplastic, a viscoelastic, or a dilatant.Useful materials for producing a malleable sac are not limited to anyparticular structure. A wide variety of materials can be configured intoa malleable sac. In one embodiment, the malleable sac is made from amaterial selected from: a metal, a polymer, a wax, a gum, a clay, or aplant hydrogel.

In one embodiment, the malleable sac is made from a thermoplastic resin.Thermoplastic resins are polymers which become a liquid when heated totheir melting point (Tm) and freeze when cooled below their glasstransition temperature (Tg). Many useful thermoplastics are known in theart. Many thermoplastics become malleable at a temperature between theirTg and Tm. In one embodiment, the malleable sac is made from athermoplastic that is malleable at a physiologically acceptabletemperature. Alternatively, the malleable sac can be made from athermoplastic that is malleable at a temperature above that which isphysiologically acceptable. In such an embodiment, the expandable devicecan comprise heating elements to impart malleability to the sac whendesired. If the device is intended for use in a live patient, thepatient can be protected from the high temperatures using a layer ofinsulation wrapped around the expandable sac that can be removed whensac malleability is no longer desired.

In one embodiment, the malleable sac is made from a viscoplastic. Aviscoplastic is a material that exhibits inelastic plastic deformation,i.e. the material undergoes unrecoverable deformations when a load levelis reached. Although viscoplastics are not limited to any particularmaterial, a viscoplastic can typically be identified as a material inwhich deformation depends on the rate at which loads are applied. Anumber of viscoplastics are known in the art. For example, manythermoplastic resins can be configured as viscoplastics.

In one embodiment, the malleable sac is made from a viscoelastic. Aviscoelastic is a material that exhibits both viscous and elasticcharacteristics when undergoing deformation. Although viscoelastics arenot limited to any particular material, a viscoelastic can typically beidentified as a material having one or more of the following properties:a) if the stress is held constant, the strain increases with time(creep); b) if the strain is held constant, the stress decreases withtime (relaxation); c) the effective stiffness depends on the rate ofapplication of the load; d) if cyclic loading is applied, hysteresis (aphase lag) occurs, leading to a dissipation of mechanical energy. Anumber of viscoelastics are known in the art. For example, manythermoplastic resins can be configured as viscoelastics.

In one embodiment, the malleable sac is made from a dilatant. A dilatantis a material in which viscosity increases with the rate of shearstrain. A number of dilatants are known in the art. For example, adilatant can comprise a cross-linked polysiloxane (e.g.polysiloxane-boron) polymer, for example, as seen in Silly Putty™, adilatant containing 65% dimethyl siloxane (hydroxy-terminated polymerswith boric acid), 17% silica (crystalline quartz), 9% thixotropic(castor oil derivative), 4% polydimethylsiloxane, 1% decamethylcyclopentasiloxane, and 1% glycerine.

In one embodiment, the malleable sac is made from a polymer. In oneembodiment, the polymer is a semi-crystalline polymer or an amorphouspolymer. In one embodiment, the polymer is a polysiloxane, a shapememory polymer, a dynamic polymer, a viscous polymer, a viscoplasticpolymer, a viscoelastic polymer, or a thermoplastic resin. Polymers areespecially useful materials for making malleable sacs because they havereadily tunable properties. The skilled artisan will recognize that theproperties of a polymer (e.g. malleability, viscosity, viscoelasticity,viscoplasticity, Tg, Tm, etc) can be tuned by configuring the polymer ina number of manners, for example, by using appropriate branching,cross-linkages, by incorporation into copolymers (e.g. block or graft)or mixed polymers, or by mixing with appropriate excipients (e.g.plasticizer).

In one embodiment, the polymer is a thermoplastic resin configured in amanner to impart malleability and/or ductility. Examples ofthermoplastic polymer types that can be configured to provide amalleable sac material include acrylates (e.g. a polymethylmethacrylate), fluoropolymers (e.g. a PTFE, a CTFE, or a PVDF),polyesters (e.g. a PET (polyethylene tetrephthalate), a PTFE(polytetrafluoroethylene), or other types of polyethylene), polyolefins(e.g. a LDPE or a PP), a polycarbonate, a thermoplastic elastomer (e.g.thermoplastic polyurethane), or a low molecular weight thermoplasticresin or a blend of a thermoplastic resin and a particulate material,for example, as described in U.S. Pat. No. 7,157,140).

In one embodiment, the malleable sac or segments thereof is made from ashape memory plastic or a macroscopically responsive structurallydynamic polymer. A shape memory plastic can be configured to take on adifferent shape following activation (e.g. by physical, chemical, orelectromagnetic radiation (e.g. light) based activation). Examples ofsuch are known in the art, for example, as described by Thompson(“Intelligent plastics change shape with light”, MIT Tech Talk; Volume49-Number 25). In one embodiment, the macroscopically responsivestructurally dynamic material is a thermoresponsive material, ahemoresponsive material, a mechanoresponsive material, a photoresponsivematerials, or an electroresponsive materials, for example, as describedby Woojteck et al. (Using the dynamic bond to access macroscopicallyresponsive structurally dynamic polymers; Nature Materials. Vol 10,January 2011).

In one embodiment, the malleable sac is made from a clay, e.g. adispersion of particles in a medium such as a plasticizer. Optionally,the clay is a polymer clay (e.g. PVC dispersed in a plasticizer) orsilica clay (silicon particles dispersed in a plasticizer).

In one embodiment, the malleable sac is made from a metal. Examplarymalleable metals include malleable metals such as gold, platinum,palladium, and silver. A malleable sac can be provided, for example, byconfigured a thin envelope made of a malleable metal. In one embodiment,the malleable sac is an envelope having a malleable metal wire frame anda transparent polymer membrane laid across the wire frame.

In one embodiment, the malleable sac is made from a wax. Useful waxesinclude carboxylic acid waxes, fatty alcohol waxes, paraffins, montanwaxes, mineral oil waxes, gel waxes, microcrystalline waxes, gels, andcracked polyethylenes,

In one embodiment, the malleable sac is made from a gum, amucopolysaccharide (e.g. Viscoat, a viscoelastic solution) or aproteoglycan (e.g. as described in European Patent ApplicationEP0466966).

In one embodiment, the malleable sac is made from a plant hydrogel.Examples of useful plant hydrogels are described, for example, in“Hydrogels, Latexes and Resins”[http://botany.csdl.tamu.edu/FLORA/328Fall98/resins.html].

In one embodiment, the malleable sac is made from a coated elastomer,e.g. as detailed in Mahdavi et al. (PNAS Feb. 19, 2008 vol. 105 no. 72307-2312). Such an elastomer can be configured in a manner to impartmalleability.

In one embodiment, the malleable sac is made from a combination ofdifferent malleable materials. Optionally, the different malleablematerials are arranged in a segmental or quilt-like manner to impartdifferential malleable characteristics to different segments of a sacwall.

In one embodiment, the malleable sac comprises a plurality of sac wallportions (‘segments’) with different malleability or deformability(resistance to deformation), for example, to provide differentialexpandability of the plurality of segments. Such a sac can be obtained,for example, by providing the portions with different malleablematerials or by configuring the portions with different thicknesses ofthe same material.

In one embodiment, the malleable sac is a pleated sac comprisingmalleable pleats (malleable fold lines).

In one embodiment, the wall of the malleable sac (or segment thereof) isprovided with a thickness such that, increased by stressing the wall (bycompressive or tensile stress), the wall surface area can be by at leastany of: 2 fold, 3 fold, 4 fold, 6 fold, or 10 fold without breaking.Optionally, the elasticity of the material is such that the wall surfacearea remains increased by at least about 20% or 50% for one minute afterthe stress is removed. The skilled artisan will appreciate that themaximum deformability (e.g. extent that a malleable sac wall can bestretched before breaking) can be dependent on the properties of themalleable material itself and the thickness of the wall.

In one embodiment, the malleable sac is configured to be expanded from acollapsed state by imparting pressure on the luminal wall (e.g. fillingthe sac with a fluid) and then remain expanded in the absence of saidpressure on the luminal wall (i.e. they are self-supporting).Optionally, the malleable sac is configured to retract an organ uponexpansion and does not collapse the stress of the organ in the absenceof luminal pressure.

In one embodiment, an expandable sac is configured with a malleabilitysuch that it can be deformed by smooth muscles but retains its shapeand/or structural integrity in the absence of luminal pressure orexternal pressure (i.e. the sac is self-supporting).

In one embodiment, an expandable sac is configured with a malleabilitysuch that it can be deformed against a body cavity wall withoutsubstantially harming the patient, but retains its shape in the absenceof luminal pressure (i.e. the sac is self supporting).

In one embodiment, the lumen of the sac comprises (or is configured tobe filled with) a fluid (e.g. viscous fluid), for example, to impartvolume to the sac by fluid pressure.

Although a collapsed malleable sac (e.g. folded or rolled) can beconfigured to expand (unfold or unroll) to a predetermined shape (e.g.upon imparting a target expansion pressure), a superior property ofexamplary malleable sacs is that the sac can be deformed beyond and/orirrespective of a preconfigured shape (e.g. shape determined whenforming a sac by molding). For example, after expansion to apredetermined shape by inflation at a first pressure, a portion of thewall (‘segment’) can be locally deformed (e.g. stretched) into a desiredfold or other small cavity (e.g. diverticulum) in the wall of a largerbody cavity.

In one embodiment, the malleable sac is transparent. A transparent saccan be made from transparent malleable polymer (e.g. a polycarbonatefilm).

In one embodiment, the device comprises a malleable sac comprising aport. Optionally, the malleable sac is an outer sac and the devicefurther comprises an inner sac in the lumen of the outer sac.Optionally, at least one of the inner or outer sacs comprises an accesstube. Optionally, both the inner and outer sacs comprise ports.Optionally, one or more of the sacs is transparent.

With the teachings provided herein, the skilled artisan can now selectmaterials appropriate for producing a malleable sac. The skilled artisanwill recognize that the malleability and/or deformability of the sac isdependent on factors such as the physical properties of the material,the thickness of the material, and the environment of the material (e.g.temperature, physical, chemical, or electromagnetic energy forcesapplied to the material).

Multilayer Devices

In one embodiment, the expandable device is a multilayer device.According to the present invention, a multilayered device comprises anouter sac and at least one inner sac in the lumen of the outer sac.

In one embodiment the inner sac is configured for expansion by beingfilled with a fluid to impart volume and shape to the outer sac (e.g.fluid pressure).

In one embodiment, the inner sac is configured for housing a tool (e.g.robot) in its lumen, for example, to compartmentalize the tool.Optionally, the expandable device comprise a plurality of inner sacs,each housing a different tool.

In one embodiment, the expandable device comprises a plurality of innersacs. Optionally, one or more inner sacs house a tool (e.g. robot) andone or more inner sacs are configured for expansion, e.g. to provide aframework to the expandable device. Optionally, the plurality of innersacs comprises different fluids (e.g. gel/gas, gas/liquid, liquid/gel).

In one embodiment, the expandable device comprises a first inner sac inthe lumen of an outer sac, and a second inner sac in the lumen of thefirst inner sac. Optionally, the space between the walls of the firstand second inner sacs is filled with a fluid, for example to cushion thecontents (e.g. robot) of the second inner sac.

In one embodiment, the expandable device comprises an outer sac, a firstinner framework sac in the lumen of the outer sac, a second inner sac inthe lumen of the outer sac, and a third inner sac in the lumen of thesecond inner sac. The second and/or third inner sacs optionally house atool in the lumen.

In one embodiment, the outer and/or inner sacs comprise ports.Optionally, an outer sac and an inner sac comprise ports that areconfigured to be aligned, for example, as detailed in Example 4. In oneembodiment, a port is provided on any sac that houses a tool (e.g.robot).

In one embodiment, the inner sac is attached or embedded to the outersac. Optionally, the inner sac provides a framework. Optionally, theframework is an inflatable conduit embedded in an outer sac. Such aconduit can be used, for example, to expand the outer sac and/or providerigidity in the outer sac. Optionally, the inflatable conduit isprovided segmentally or localized about the outer sac, for example toprovide expansion and/or rigidity in some segments of the outer sac wallbut allow other segments to remain flexible. The conduit can also beconfigured as a rail (inflatable rail) that serves as both a frameworkfor the device and a rail for guiding railed devices.

In one embodiment, a multilayer device comprises sacs provided in any ofthe following arrangements: arranged as

-   -   a. Successive;    -   b. Contiguous;    -   c. Budding out from each other (evaginating);    -   d. Budding in (invaginating);    -   e. Involuting (shaped in whorls that obscure their axis of        location);

Expansion

An expandable sac of the present invention is configured for expansionfrom a collapsed state. The present invention contemplates devicesconfigured in any manner that allows expansion by any mechanism.

In one embodiment, the envelope (wall) of an expandable sac canconfigured for expansion by providing the sac as any of: a flexibleenvelope (e.g. membrane), a malleable envelope, a pleated envelope, or acombination thereof.

In one embodiment, a sac is configured for expansion by fluid pressure,i.e. by filling the sac with a fluid (e.g. inflation). Optionally, a sacconfigured for expansion by fluid pressure is fluidly connected to anaccess tube. In another embodiment, the sac is configured for expansionby an expandable framework (e.g. “T” framework for placement between twoorgans).

Useful fluids that can be used to expand a sac include gasses, liquids,gels, viscous liquids, and particulates or semi-solids that can bepumped or otherwise filled into a sac to cause expansion of the sac. Inone embodiment, the device comprises one or more access tubes fluidlyconnected to one or more sacs of the device such that a fluid can bepumped in (or out) of the one or more sacs, thereby expanding thesac(s). Optionally, the access tube is flexible (optionally malleable)to allow curves in the tube. In such an embodiment, the access tube canbe connected to a fluid pump provided outside of the patient (or otherwork environment). As an alternative to an access tube, an expandablesac can contain a pressurized vessel, filled with the fluid, comprisinga fluid release valve that allows release of the pressurized fluid intothe lumen of the expandable sac, thereby expanding the sac.

Useful expandable mechanical frameworks include a framework of one ormore inner sacs that are expandable (e.g. by fluid pressure), e.g. asdetailed in or an expandable scaffolding, for example, a magneticallydetailed in US 2009/0287293 (Mailhot).

In one embodiment, the expandable sac is configured to fold along one ormore segments, for example, by providing pleats that are flexible ormalleable.

In one embodiment, an expandable sac is configured for expansion bypleating and/or packing (e.g. telescopically) segments of the sac wallin any known manner of pleating or packing such that expansile pressureexerted by any mechanism can unfold or lengthen the sac wall.

In one embodiment, the sac is configured expansion upon the lumenreaching a target expansion pressure. Optionally, the target expansionpressure is less than about any of: 100 psi, 75 psi, 50 psi, 25 psi, 10psi, 5 psi, 2 psi, or 1 psi. Optionally, the target expansion pressureis greater than about any of: 1 psi, 2 psi, 5 psi, 10 psi, 20 psi, 30psi, 50 psi, or 75 psi. Such a sac is not limited to a sac made from anyparticular material. The skilled artisan will recognize that a sac'starget expansion pressure is dependent on the properties of the sacmaterial, the thickness of the sac wall, and the environment of the sac(e.g. temperature). Optionally, the sac has a plurality of targetexpansion pressures. For example, the sac can be configured a folded sacwith a plurality of pleats, some of which unfold at a first targetpressure, and some of which unfold at a second target pressure. Asanother example of a sac with a plurality of target expansion pressures,a malleable sac can be collapsed (e.g. folded or rolled) and configuredto expand (unfold or unroll) at a first target pressure and then deform(e.g. by stretching) at a second target pressure. Such a sac with aplurality of target expansion pressures is useful, for example, toinduce one expanded shape at the first target pressure, and then asecond expanded shape (predetermined or not) at the second targetpressure. Optionally, the second target pressure is provided by meansother than inflation, for example, a sac shaping tool such as a robotthat presses against the luminal wall. Malleable sacs are especiallyuseful for providing such a configuration.

An expanded sac can be collapsed by any means, for example, to retractthe device out of a body cavity through a small incision or otherpassageway. For example, the sac can be configured to collapse byevacuation or clearing of a fluid filled therein. Additionally oralternatively, an expanded sac can be collapsed using forceps or othermeans to squeeze the sac into a collapsed state. Additionally oralternatively, a malleable sac can be optionally configured to becollapsed by cold-shrinking the sac.

In one embodiment, the lumen of the sac comprises (or is configured tobe filled with) a viscous fluid, for example, to impart volume to thesac.

In one embodiment, one or more robots (e.g. microrobots) are providedfor moving and/or coupling access tubes, inner sacs, or frameworks asneeded. For example, robotic devices moving as railed or non-raileddevices can open or close access tube connections in conduits to fill orempty the conduits, Alternately, robotic devices insert a tubularconduit (or segment thereof)- a free-standing conduit (as opposed tonetwork of embedded conduits in wall of the sac) into the embeddedconduit portals in order to remove and divert the fluid into an adjacentsac or else into a main transport tube (in order to remove the fluid outof the expandable device entirely).

Additional means to expand a sac(s) and simultaneously to shape sac(s)as desired include: deploying an expandable framework or a solid,lattice framework into a preconfigured shape and then adding orsubtracting from the framework or else modifying the shape of theframework using robotic devices. This can occur, as an example, byintroducing a heating tool on the robotic device to a modular segment ofa framework, thereby shrinking its size thus imparting a desired shapeneed for the optimal performance of the procedure on the target organ ortissue.

In one embodiment, a substantially viscous material flows in the saclumen imparting shape to the sac.

In one embodiment, the a fluids expansion and/or lubrication between thewalls of an inner and outer sac.

In one embodiment, fluid supplied to the inner wall of the sac changesits elasticity (e.g. in a material having environment-dependentproperties) imparting additional expandability in targeted segments ofthe wall of the sac.

In one embodiment, the expandable sac is filled with micro-crystallinecollagen, for example, for incorporation in any sac wall for segmentedor localized thickening of wall sacs. Examples of such micro-crystallinecollagen are described in U.S. Pat. No. 3,443,261.

In one embodiment, the expandable sac is filled with a chitosan, forexample, which can be configured to interchange between a liquid andsolid like state. This is useful, for example, as a sac wall compositionand for shaping an expandable sac in either in a diffuse or segmentalmanner. As example of such chitosan is described by Chenite et al.(Biomaterials. 2000 November; 21(21):2155-61. Novel injectable neutralsolutions of chitosan form biodegradable gels in situ).

In one embodiment, gas or liquid contents can be removed by tubularattachments or else rendered into another more convenient form such as apowder (e.g. by mixing with a powder or by freezing) without beingallowed to react with the body linings.

Ports

In one embodiment, the device comprises one or more ports in a sac wall.A port according to the present invention is a passageway in a sac wallconnecting the lumen of the sac with the periphery of the sac.Optionally, a port of the device is sized to allow passage of a toolthere through, for example, a d/t device.

In one embodiment, the port is a valve. A valve is a port configured tohave two states: opened and closed. The port can be any type of known inthe art. For example, the port can be a two way valve such as abutterfly valve, a ball valve, a slide valve, or a self-sealing valve.Optionally, the valve is configured to provide a fluid-tight seal whenclosed and allow passage of a tool through it when open. Optionally, thedevice comprises a valve actuator for opening and/or closing the valve.

In one embodiment, the expandable device is a multilayer devicecomprising an inner and outer sac, wherein both sacs have a port.Optionally, the ports are configured to align to allow the passage of atool from the lumen of the inner sac to the periphery of the outer sac.

In one embodiment, ports comprise an adhesive, for example, to provide afluid-tight seal.

A port allows access to the periphery of the sac wall (e.g. by robotpassing there through).

Railed Devices

In one embodiment, the expandable device has a rail system comprising arail and a railed device coupled to the rail for movement there on.Useful railed devices comprise a rail coupler for coupling the raileddevice to the rail for movement there on. Optionally, the coupler isconfigured for supporting, stabilizing and/or securing the railed deviceon the rail. Optionally, the railed device comprises a motor for movingthe railed device along the rail.

In one embodiment, the railed device carries a tool. The tool can be anytool (e.g. as taught herein). For example, the tool can be a robot, amicrorobot, a d/t instrument, or a housekeeping tool. Such a raileddevice can be used, for example, to transport and position the tool.

In one embodiment, the railed device is tethered to a sac wall.Optionally, a plurality of railed devices are tethered to a sac wall.Examples of such are detailed in Example 5 and Example 13. Such a raileddevice can be used, for example, to move or position a sac wall, forexample, to move the entire expandable device, a portion of the sacwall, or to impart bends or articulations in the sac wall. Optionally,the railed device is tethered to the sac wall by retractable pylon (i.e.an attachable/detachable tether). Such a railed device can be used toselectively or transiently tether a desired segment of the sac wall formovement thereof. A retractable pylon can interface the sac wall, forexample, using clips, magnets, key/keyhole combinations and the like.

The rail coupler can be any coupler that couples the railed device tothe rail for movement thereon and optionally supports, stabilizes,and/or secures the railed device on (or in) the rail. In one embodiment,the rail coupler comprises any of: a wheel, a protrusion, a cavity, asled, a walking member, a gear, a pulley, a hook, or a magnet. A wheelcan be used, for example, to roll a railed device on a rail. Aprotrusion can be used, for example, sit a railed device in a groove ofa rail (e.g. in grooved rails or grooved fluidic rails). A cavity (e.g.groove) can be used, for example, to sit and/or stabilize a raileddevice on a protrusion of a rail. A sled can be used, for example, toslide a railed device about a rail. A walking member (e.g. appendages asknown for walking robots) can be used, for example, to transientlycontact a rail as a railed device walks about the rail. A gear can beused, for example, to interface with a rack as in a rack and pinionconfiguration. A magnet can be used, for example, to stabilize a raileddevice to the rail or levitate a railed device on a rail. A hook can beused, for example, to secure a railed device to a rail. A pulley can beused, for example, to couple the railed device as a conveyor belt-typedevice. Optionally, the rail coupler is configured for coupling in arailed microfluidics rail system, for example, as described by Chung etal. (“Guided and fluidic self-assembly of microstructures using railedmicrofluidic channels”; Nature Materials 7, 581-587 (2008)). Couplersthat provide stabilization or securing of the railed device optionallykeep the railed device in contact with the rail, for example, to avoidderailing of the railed device. Such a coupler can be used to keep therailed device in the proper orientation and/or to provide verticaland/or lateral support, e.g. to avoid the railed device from tippingover or falling off the rail. Examples of useful components for suchstabilization or securing include hooks, magnets, cavities, protrusions,as described above.

Motors

In one embodiment, a railed device comprises a motor for moving therailed device along the rail. The motor can be any motor that impartssuch movement along the rail.

Useful motors include linear actuators, inchworm motors, electromagneticmotors, and the like.

In one embodiment, the motor is a linear actuator. Examples of linearactuators of any of the following types: rotary stepper motors, rotaryservo motors, voice coil, screw, piezoelectric device, solenoid, orpneumatic pump actuators. Examples of such linear actuators are wellknown in the art.

In one embodiment, the motor is an inchworm motor. An inchworm motor isa motor comprising at least two railcars, a lead car and a trail car,wherein each rail car moves independently to provide an inchworm-likemovement. An inchworm motor operates by extending the lead railcar (e.g.moving along the track) and then stopping or slowing the first railcar,and then moving the second (or additional) railcar to meet the firstrail car. Optionally, the inchworm motor is an electromagnetic inchwormmotor, wherein the movement of one or more rail cars is imparted byattractive/repulsive magnetic forces. Optionally, the inchworm motor isan attach-extend type motor, wherein one car is transiently mechanicallyfixed to the rail (by breaking means such as a friction pad or clamp)and another car is pulled to or pushed from the fixed car.

In one embodiment, the inchworm motor is an electromagnetic motor. Anyinchworm type electromagnetic motor is useful according to the presentinvention.

In one embodiment, the motor is an inchworm type electromagnetic motorcomprising three railcars, a lead car, and intermediate car, and a trailcar, each comprising an electromagnet, for example, as detailed inExample 1 and Example 2. Optionally, the railed device comprises adistance limiter for restraining the cars from moving a maximum distancefrom each other (e.g. a cable or membrane). In such a motor, theelectromagnets are configured to attract and repel the electromagnet(s)on adjacent cars, thereby moving at least one car. Although anelectromagnetic inchworm motor can be configured as an attach-extendtype motor, the inventor has surprising discovered that the motor can beconfigured without a means of fixing (breaking) the railcars to therail. In such a three-car electromagnetic motor, the rail cars can beconfigured with the following specifications: the intermediate carweighs less than the lead and trail car, the lead car weighs less thanthe intermediate car and the trail car combined, and the trail carweighs less than the lead and intermediate car combined, e.g. asdiscussed in Example 2.

This configuration surprisingly provides for inchworm-type movementwithout requiring any car to be transiently fixed to the rail becauseone or more heavier rail cars (i.e. cars with greater inertiaconsidering mass and friction) remain relatively stationary while alighter car (i.e. cars with less inertia considering mass and friction)moves by electromagnetic forces (repulsion or attraction) imparted byinteraction of the electromagnets. Such an electromagnetic motor is alsouseful alone, for example, without an expandable device of the presentinvention and/or without a rail.

In one embodiment, the inchworm motor is an attach-extend type motor,wherein one car is transiently mechanically fixed to the rail and theother car is moved relative to the fixed car (e.g. by attraction orrepulsion). An attach-extend type motor comprises at least two cars,wherein a first rail car comprises mechanical fixing means (e.g. clampor break) and the motor comprises means for movement of the second railcar relative to the first rail car, for example, by attraction orrepulsion (e.g. spring, magnet, electromagnet, linear actuator). Thefixing means can be a clamp such as a piezoelectric clamp or afriction-inducing means such as an electromagnet. Examples of usefulattach-extend type inchworm motors and other motors are described inU.S. Pat. No. 6,040,643, US 2009/0115284, U.S. Pat. No. 6,380,661, andTucker (“Actuation for Mobile Micro-Robotics”; Obtained from the URL:http://www.ece.ncsu.edu/erl/microrobotics/actuation/actuation.html on 28Sep. 2011).

Another useful inchworm motor is described by Fuchiwaki et al.:(“Development of 3-DOF Inchworm Mechanism for Flexible, Compact,Low-Inertia, and Omnidirectional Precise Positioning: Dynamical Analysisand Improvement of the Maximum Velocity Within No Slip ofElectromagnets”; Mechatronics, IEEE/ASME Transactions on; Volume: PPIssue: 99, page(s): 1-12).

Other useful motors include any motors known in the art for movingrobots or microrobots or used for movement in micro-electromechanicalsystems (MEMS).

Although the motors described herein can be used to move a railed deviceabout a rail, the invention also contemplates expandable devicescomprising non-railed robots comprising any of said motors as a meansfor movement.

Rails

According to the present invention, an expandable device optionallycomprises a rail such that a railed device can move along the rail. Therail can be coupled to the sac by providing the rail in the lumen of thesac and/or providing one or more attachment points between the sac andthe rail. The rail can be any member configured to support to a raileddevice and provide a track along which the railed device can move.

In one embodiment, the rail is any of: flexible or rigid, fragmented orcontinuous, embedded in the sac wall, mounted to the sac wall,contiguous or discontiguous with the sac wall.

In one embodiment, the rail provides a member configured to providelateral support to a railed device. Optionally, the member is aprotrusion or a groove.

In one embodiment, the rail is permanently or reversibly fixed to thesac.

In one embodiment, the device comprises a plurality of rails.Optionally, the plurality of rails is in the same sac. Optionally, theeach of the plurality are in different sacs.

In one embodiment, the rail is a flexible rail. Such a rail is useful,for example, to allow the rail to change shape in order to bend aroundcorners and/or fit through small passageways as the expandable sac ismaneuvered in or through a body cavity.

In one embodiment, the rail is a fragmented and/or modular railconfigured for assembly and disassembly within the expandable sac. Sucha rail is useful, for example, for providing a device that can beinserted into a body cavity and expanded, and then assembling the rail.An example of such a rail is described in US 2009/0076536 (Rentschler etal.) Optionally, the rail is configured for self-assembly, for example,provided as a plurality of fragments tethered to microfluidic channels.Optionally, the rail is configured as a plurality of fragmentsconfigured into an expandable canopy, for example, fragments anchored tothe luminal sac wall configured for assembly upon expansion of the sac.

In one embodiment, the rail is an inflatable rail. An inflatable railcomprises a conduit made from a flexible material and is configured tobecome relatively turgid pressurized when filled with a fluid or whenfluid flows through the conduit. In such an embodiment, the rail isflaccid when the conduit is not pressurized (not filled with a fluid)and becomes turgid upon pressurizing the lumen of the conduit, therebyforming a functional rail. In this configuration, the collapsed andflaccid state of the rail allows the rail to bend as needed while thedevice is maneuvered through a patient until it reaches the target site.When desired, the rail system can be inflated into its turgid state toprovide support to railed devices such that the railed devices can movealong the rail. Optionally, the rail comprises a fork in the conduit,wherein the form splits a single conduit into a plurality of conduits,wherein each of the plurality of conduits can support a railed devicewhen turgid. Optionally, the fork comprises a control circuit configuredto differentially control the flow of fluid from the single conduit intothe plurality of conduits. In such a configuration, the user can choosewhich of the plurality of conduits to fill to turgidity and which tokeep in their flaccid state. Optionally, the control circuit is afluidic amplifier, for example, as detailed in U.S. Pat. No. 4,000,757(Freeman). Such a rail is also useful outside of (without) an expandabledevice of the present invention.

In one embodiment, the rail is an inflatable rail embedded in orcontoured against the sac wall. Optionally, the rail imparts rigidity toa flexible sac wall when the rail is inflated to turgidity.

In one embodiment, the rail is fluidic channel (e.g. microfluidicchannel). Such a fluidic channel can be configured to provide hydraulicfluid. In one embodiment, the fluid is supplied in the wall of the sacthrough an expandable network of channels forming a rail networkembedded in the wall of the sac as known in fluidics technology. Therailed devices can, for example, comprise a protrusion that locks intothe fluidic channel and is propelled by the fluid pressure.

In one embodiment, the rail is contiguous with the sac. Optionally, sucha rail is embedded and/or formed as a mold with the sac (e.g. made ofthe same material as the sac). Optionally, the such a rail is made froma malleable material.

In one embodiment, the rail is discontiguous with the sac, for example,tethered to the sac at one or more locations.

In one embodiment, the device comprises a plurality of rails arrangedlongitudinally with respect to each other. Such a configuration can beused, for example, to provide different railed devices at differentlocations in an expandable sac, for example, to localize a tool (e.g.microrobot) at a specific segment of the expandable sac or to move (bytethered motorcar) a specific segment of the sac wall.

In one embodiment, the device comprises a plurality of rails arrangedlaterally (e.g. parallel) to each other. Optionally, each of the railscomprises a railed device tethered to a different portion of the sacwall, for example, portions of the sac wall that aren't in proximity toeach other (e.g. opposite or parallel walls). Such a configuration isuseful for example, to provide bends, curves, or articulations in wallsegments of the device, or to impart a “wiggling” motion, i.e. curvingor contracting one wall using movement of a railed device (tetheredmotorcar) on one rail, and then curving or contracting the other wallusing movement of a railed device (tethered motorcar) on the other,laterally spaced rail). An example of such is detailed in Example 13.

In one embodiment, the rail is any rail that provides a support forsecuring a railed device there to and does not block a tool carried bythe railed device from accessing the lumen (e.g. luminal wall) of thesac. Not included in this embodiment are rails that are themselves acontiguous enclosure (tube) through which a railed device and a tool (inits entirety) travel.

In one embodiment, the rail system comprises a railed device tethered tothe sac wall (‘tethered motorcar’) and the rail is not attached to thesac wall at a location in close proximity to the tether on the wall (toallow movement of the wall segment at the tether to move about the railalong with the railed device).

Other useful rails are described, for example, in US 2009/0076536(Rentschler et al.).

Tools

An expandable device of the present invention comprises an expandablesac comprising at least one tool. Optionally, the tool is carried by arailed device.

Useful tools according to the present invention include robots,diagnostic and therapeutic (‘d/t’) instruments, housekeeping tools thatcan be manipulated to move or shape a sac or sac component, stabilizingtools configured to stabilize another tool or hand-operated equipment,and tools that can deploy, modify, or assemble other tools or devices.

In one embodiment, one or more tools are fragmented or foldable.Fragmented tools are those whose parts can be configured together afterdisassembly to form a functional tool. Foldable tools are those whichcomprise parts that can be folded or collapsed on each other andunfolded or expanded to form a functional tool. Optionally, the tool isfragmented and configured for self-assembly. Optionally, the foldabletool is configured for self-unfolding as is known in the art. In suchembodiments, the tools can be inserted into a patient transported to thetarget site as fragmented or folded tools and then re-assembled orunfolded at the target site. Optionally, the fragments of a fragmentedtool are carried on different rails (‘cooperating rails’), e.g. asdescribed by Chung et al. (“Guided and fluidic self-assembly ofmicrostructures using railed microfluidic channels”; Nature Materials 7,581-587 (2008)). Optionally, cooperating rails position the fragments inproximity to each other for assembling.

In one embodiment, one or more tools are either attached to the wall ofthe sac or carried on a rail. A tool that is attached to the wall of asac is optionally, attached via tether, adhesive, magnetic, mechanicalor other attaching means for permanently or reversibly attaching toolsor devices to the sac wall. For example, magnets (or other holding meanssuch as clips) embedded in the sac wall can serve to hold or stabilize ametal toolbox in which a sharp tool (e.g. cutting blade) or volatilesubstance is segregated from the remainder of the sac lumen (e.g. untilneeded at a target site).]

In one embodiment, an expandable sac provides a protective cushionand/or protective envelope for one or more tools.

In embodiment, one or more tools (e.g. suction, irrigation, orelectrical tools) are coupled to a flexible access tube of a sac foroperation thereof. Such an access tube allows external equipment such asfluid pumps, power supplies, videos monitors, and the like, to becoupled to tools in the sac.

In one embodiment, one or more tools are delivered to or removed fromthe expandable sac through an access tube after the expandable sac hasbeen positioned in body cavity.

In one embodiment, the sac comprises sensors (e.g. motion sensors),functional and/or structural units (e.g. filaments, piezoelectricfilaments, magnets), expandable conduits and tracks, or pre-formedconduits and tracks, for example, embedded in the sac wall. [Reference:Kim et. al., Materials for multifunctional balloon catheters withcapabilities in cardiac electrophysiological mapping and ablationtherapy. NATURE MATERIALS j VOL 10 j APRIL 2011www.nature.com/naturematerials.]

Robots

In one embodiment, the device comprises a robot, for example, amicrorobot. Typically, a robot comprises an arm or other component thatis actuated along one or more axes, for example, linear axes orrotational axes (e.g. imparted by a pivoting arm). The robot cancomprise a d/t instrument or other tool attached to the arm. Optionally,the robot comprises a transport mechanism for gross movement of therobot as a whole (e.g. is carried by a railed device) and an actuatorfor movement of only part of the robot such as an arm connected to aninstrument or other tool. The invention contemplates the use of anyknown robots, microrobots, or parts thereof.

Useful robots include fully assembled robots, fragmented (andassembleable) robots, or folding (collapsible) robots.

The invention contemplates the use of robots having any mechanism fortransport about the expandable sac device. Optionally, the robot iscarried by a railed device. Alternatively, the robot can be transportedby any other means, for example, wheels, walking components, orcomponents for snake-like movements. Other useful mechanisms for robottransport are known in the art.

In one embodiment, the robot is a microrobot, for example, a robot witha cross-section of less than about any of: 4 cm, 3 cm, 2 cm, or 1 cm.Examples of useful micro robots are well known in the art, for example,as described by Forgione et al. [Surg Oncol. 2009 June; 18(2):121-9.Epub 2009 Jan. 14. “In vivo microrobots for natural orifice transluminalsurgery. Current status and future perspectives.]

In one embodiment, the robot is has cross-section of greater than aboutany of: 4 cm, 3 cm, 2 cm, or 1 cm.

In one embodiment, a robot (e.g. microrobot) is configured to performany of the following functions: tissue removal, tissue biopsy, targeteddrug delivery, carrier of a radioactive seed, ablation, cryoablation,thermoablation (e.g. using heating elements such as RF or ultrasonicheating elements), stenting, carrier of electrodes, sensing (e.g.oxygen), cutting device, probing device, or carrier of an implant. Therobot (e.g. microrobot) can be a railed device or a non-railed device.

In one embodiment, the robot comprises a means for transportation.Optionally, the means for transportation of a robot (e.g. microrobot)comprises any of propeller, cilia/flagellae, electromagnetic pump, jetpump, membrane propulsion (rapidly vibrating membrane), appendages forcrawling, moving coil linear actuator, moving magnet actuator,electromagnet actuator, piezoelectric actuator, electrostatic actuator,or electrothermal actuator. Examples of useful transport mechanisms forrobots (railed or non railed) include: helical propellers,traveling-Wave propulsion, and external magnetic field creation, forexample, as described by Nelson et al. (“Microrobots for MinimallyInvasive Medicine”; Annu. Rev. Biomed. Eng. 2010. 12:55-85). Otherexamples of useful transport mechanisms include vibrational structureand three legs, e.g. as described by Hou et al. (“Design and Fabricationof a Miniature Railway Vehicle”; World Academy of Science, Engineeringand Technology 51 2009, p 49-53), and tethered or untethered MEMS (e.g.scratch drive actuator). Other examples of useful transport mechanismsinclude an array of prismatic joints, for example, as described by(Murthy et al. ARRIpede: An Assembled Micro Crawler; Nanotechnology,2008. NANO '08. 8th IEEE Conference on; 18-21 Aug. 2008, pages 833-836),SMA-actuated segmented microrobot, e.g. as described in “Development ofa biomimetic miniature robotic crawler” (Autonomous Robots, Volume 21,Number 2, 155-163) or fluidic rail systems, e.g. as described by Chunget al. (“Guided and fluidic self-assembly of microstructures usingrailed microfluidic channels”; Nature Materials 7, 581-587 (2008)). Anyof such means for transportation can also be configured to transport theexpandable device as a whole (i.e. globally).

In one embodiment, the expandable device comprises a fragmented robot ora folding robot (collapsible and/or articulated). Optionally, thefragmented robot is any of the following assembling types: key/keyholeor other latching, magnetic assembly, pull string assembly, chain-basedor lattice based self-assembling robot. Other examples of fragmentedrobots are well known in the art. An example of a pull string assemblingrobot is detailed in Example 14. An example of a key/keyhole latch isdescribed by Chung et al. (“Guided and fluidic self-assembly ofmicrostructures using railed microfluidic channels”; Nature Materials 7,581-587 (2008)). Other examples of fragmented robots are described, forexample, by Stoy et al. (“Modular Robots: The State of the Art”;Proceedings of the IEEE 2010 International Conference on Robotics andAutomation workshop 3 May 2010, Alaska, Ak., USA).

Useful microrobots that can be provided in an expandable device of theinvention include those described by Nelson et al. (“Microrobots forMinimally Invasive Medicine”; Annu. Rev. Biomed. Eng. 2010. 12:55-85),and Cepolina et al. (“A family of corobotic surgical set-ups”.Industrial Robot: An International Journal, 30(6):564-574, 2003polypyrrole-gold bilayer based microrobots, e.g. as described by Jagaret al. (“Microrobots for Micrometer-Size Objects in Aqueous Media:Potential Tools for Single-Cell Manipulation; SCIENCE VOL 288 30 Jun.2000).

A robot can have one or more actuators. FIG. 11 depicts a useful roboticrailed device 116 comprising a rail coupler 134, a motor (one of threeelectromagnets) 133, a tool holder 127, and one or more actuators 128,130, 131, 132 (rotational actuators), 129 (linear actuator).

Other useful microrobots include those used in micro-electromechanicalsystems (MEMS).

Other useful robots and are described in US 2008/0058835 (Farrior etal).

Diagnostic and Therapeutic Instruments

In one embodiment, the device comprises one or more d/t instruments.Optionally, the instrument is a robotic device. Optionally, the d/tdevice is an actuated or non-actuated instrument. For example, the d/tinstrument can be provided on an actuated (e.g. telescoping) armconfigured to move the d/t instrument through a port and access theperiphery of the sac. Additionally or alternatively, the instrument canoptionally be actuated to perform micro-movements (such as closing ofgripper jaws).

In one embodiment, the device comprises one or more diagnosticinstruments selected from: a sensor (e.g. motion or light sensor), animaging device, a camera, a stereoscope, an ultrasound sensor or imager,a light source (e.g. fiber optic), infra red, pressure (e.g.piezoelectric sensor) or temperature sensors, or MEMS sensors. Any ofsuch instruments can be configured as robotic instruments and/or carriedby a railed device. Alternatively, a diagnostic instrument such as inimaging device is not carried by a railed device.

In one embodiment, the device comprises one or more therapeuticinstruments selected from: forceps, gripper jaws, an ablation tool, acauterizer, a laser, a cryogenic ablation tool, a thermal ablation tool,an ultrasound ablation tool, a snare, a cutting tool, a microneedleholder, a needle drive, scissors, a sonic device, suction device,irrigation, a sawing tool, a boring tool, a fluid spraying device, aretraction tool, a stretching tool, a stapling tool, a puncture biopsytool, a blunt dissection tool, a sharp dissection tool, a scooping tool,and a wiping tool. Any of such instruments can be configured as actuatedand/or robotic instruments.

In one embodiment, the expandable device comprise a therapeutic toolselected from: radioactive substances healthy tissue, biological agents(e.g. living cells, bacteria, animals, worms, leaches, worms) orplant-derived substances. Optionally, the therapeutic tools is containedwithin an inner sac (e.g. ported inner sac) in the lumen of the outersac.

In one embodiment, the expandable device is configured for suctionand/or irrigation of body fluids (e.g. blood). Optionally, is suction isprovided by an aspiration tube or a sponge in or on the expandabledevice. Optionally, the expandable device comprise and inner saccomprising an aspiration tube or sponge. Optionally, the expandabledevice comprises an outer sac comprising an aspiration tube or a sponge.Optionally, a is provided sponge external to an outer sac, e.g. it is anadjoining sac and/or is configured to be dragged along, absorbing thedesired fluids from the abdominal space.

In one embodiment, one or more mini cameras (e.g. pill cams) and one ormore lighting sources are embedded along an expandable sac wall (e.g. anouter sac).

Shaping and Movement Tools

In one embodiment, the device comprises one or more tools configured tobe manipulated to move or shape an expandable sac or component thereof(housekeeping robot).

Examples of such tools include robotic arms (e.g. microrobot) and innersacs that can be expanded to shape an outer sac.

Other examples include: structural units embedded in the wall of anexpandable that sac can be employed to shape the sac. For examplefilaments, piezoelectric filaments, or. magnetized structural units(e.g. embedded in a sac wall) can be brought into contiguity using anymeans to move the walls or segments of wall of concentric or adjacentsacs. Alternately, conduits for fluid embedded in the wall of any of theexpandable sacs can conduct fluid to given segment of the sac walllending rigidity or structural stability to the targeted segment (e.g.when the conduits become turgid). Alternately, a small movable nozzlecan function as a shaping tool when moved on a rail into proximity witha segment of a sac wall directing a stream of fluid against the luminalwall of the targeted segment thereby expanding the wall differentiallyfrom the non-targeted area. Alternately, filaments embedded in the sacwall can expand or contract or coalesce together when subjected to heat,light or other activators using for example a heat or light emittingdevice mounted onto a rail that is transported to the targeted segmentof the sac wall. Expandable or assembled frameworks are also useful toimpart shape to the sac(s).

Stabilizing Tools

In one embodiment, the device comprises one or more stabilizing ororienting (‘stabilizing’) tools configured to stabilize another tool orhand-operated equipment. In such an embodiment, the expandable sacdevice can be used to expand a body cavity and the stabilizing tool canbe manipulated to orient the equipment for a given procedure. Examplesof such stabilizing tools include an expandable sac configured to allowplacement of hand-operated surgical equipment, for example, to aid aphysician during a medical procedure such as a laparoscopic procedure.Such an expandable sac is optionally configured to expand to a volumethat leaves a substantial void between the inner and outer sac to allowmanipulation of the surgical equipment. Additionally or alternatively, astabilizing tool comprises a plurality of stabilizing tools (e.g. sacs)configured to sandwich a hand operated equipment or other tool.

Expandable, assembled, or otherwise configured framework structureswithin the sac wall or lumen of the sac can also form desired cavityspace and impart stability and orientation parameters for operation ofthe hand operated equipment or other tools.

Combinations of Tools

In one embodiment, the device comprises a combination of tools.Optionally, the combination includes any combination of robots,diagnostic and therapeutic (‘d/t’) instruments, shaping or movementtools, and stabilizing tools. Optionally, one or more of the tools (e.g.each tool of the combination) is carried by a railed device and/or arobot. Optionally, the d/t instruments that have moving parts arecarried and/or operated by a robot (e.g. microrobot).

In one embodiment, the device comprises one or more diagnosticinstruments and one or more therapeutic instruments. Optionally, thediagnostic and therapeutic instruments are robotic instruments and/orare carried by a railed device.

In one embodiment, the device comprises one of the followingcombinations of d/t instruments (‘COMBOS’):

1. camera, lighting instrument, suction instrument, and irrigationinstrument.2. camera, lighting instrument, suction instrument, irrigationinstrument, and forceps instrument.3. camera, lighting instrument, suction instrument, irrigationinstrument, forceps instrument, and cutting instrument.4. camera, lighting instrument, suction instrument, irrigationinstrument, forceps instrument, cutting instrument, and clip providinginstrument.6. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument andultrasonic imaging probe device.7. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device and cryoablation instrument.8. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device and radiofrequency ablation instrument.9. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, and cryoablation instrument orradiofrequency ablation instrument.10. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, cryoablation instrument orradiofrequency ablation instrument, and retraction instrument.11. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, ablation instrument (radiofrequencyand/or cryoablation), retraction instrument and blunt dissectioninstrument.12. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, ablation instrument (radiofrequencyand/or cryoablation), retraction instrument, blunt dissection instrumentand therapeutic substance application instrument (e.g. glue).13. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, ablation instrument (radiofrequencyand/or cryoablation), retraction instrument, blunt dissectioninstrument, therapeutic substance application instrument (e.g. glue) andtelescoping instrument fitted with any one or more of the instrumentsdescribed above at its distal end.14. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, ablation instrument (radiofrequencyand/or cryoablation), retraction instrument, blunt dissectioninstrument, therapeutic substance application instrument (e.g. glue),telescoping instrument fitted with any one or more of the instrumentsdescribed above at its distal end and snaring instrument.15. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, ablation instrument (radiofrequencyand/or cryoablation), retraction instrument, blunt dissectioninstrument, therapeutic substance application instrument (e.g. glue),telescoping instrument fitted with any one or more of the instrumentsdescribed above at its distal end, snaring instrument and sewinginstrument.16. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, ablation instrument (radiofrequencyand/or cryoablation), retraction instrument, blunt dissectioninstrument, therapeutic substance application instrument (e.g. glue),telescoping instrument fitted with any one or more of the instrumentsdescribed herein at its distal end, snaring instrument, sewinginstrument and heating instrument.17. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, ablation instrument (radiofrequencyand/or cryoablation), retraction instrument, blunt dissectioninstrument, therapeutic substance application instrument (e.g. glue),telescoping instrument fitted with any one or more of the instrumentsdescribed herein at its distal end, snaring instrument, sewinginstrument, heating instrument and sensing instrument (e.g., light,motion, pressure, or temperature).18. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, ablation instrument (radiofrequencyand/or cryoablation), retraction instrument, blunt dissectioninstrument, therapeutic substance application instrument (e.g. glue),telescoping instrument fitted with any one or more of the instrumentsdescribed herein at its distal end, snaring instrument, sewinginstrument, heating instrument, sensing instrument (e.g., light, motion,pressure, or temperature) and clamp applicator instrument.19. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, ablation instrument (radiofrequencyand/or cryoablation), retraction instrument, blunt dissectioninstrument, therapeutic substance application instrument (e.g. glue),telescoping instrument fitted with any one or more of the instrumentsdescribed herein at its distal end, snaring instrument, sewinginstrument, heating instrument, sensing instrument (e.g., light, motion,pressure, or temperature), clamp applicator instrument and hookinstrument.20. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, ablation instrument (radiofrequencyand/or cryoablation), retraction instrument, blunt dissectioninstrument, therapeutic substance application instrument (e.g. glue),telescoping instrument fitted with any one or more of the instrumentsdescribed herein at its distal end, snaring instrument, sewinginstrument, heating instrument, sensing instrument (e.g., light, motion,pressure, or temperature), clamp applicator instrument, hook instrumentand speculum instrument.21. camera, lighting instrument, suction instrument, irrigationinstrument, forceps, cutting instrument, clip providing instrument,ultrasonic imaging probe device, ablation instrument (radiofrequencyand/or cryoablation), retraction instrument, blunt dissectioninstrument, therapeutic substance application instrument (e.g. glue),telescoping instrument fitted with any one or more of the instrumentsdescribed herein at its distal end, snaring instrument, sewinginstrument, heating instrument, sensing instrument (e.g., light, motion,pressure, or temperature), clamp applicator instrument, hook instrument,speculum instrument and screw fixation instrument.22. sensing instrument (e.g., light, motion, pressure, or temperaturesensing instrument), used alone or in combination with other tools23. camera (e.g. infrared camera) used alone or in combination withother tools24. lighting instrument used alone or in combination with other tools

Examples of uses for instrument combinations include:

COMBO #1 (from above): The expandable device in this configuration canbe used, for example, to perform an explorative procedure, for instanceto ascertain whether there is bleeding from the site of removal of afriable polyp during a colonoscopy in the large intestine of a patientwith diminished blood clotting capacity. For instance, if the patientcannot undergo another colonoscopy, in this scenario, the expandabledevice is deployed by insertion into the rectum and from there it ispropelled with its own means of mobility assisted by someantiperistaltic movement of the patient's colon, which contracts on theexpandable device (one of its inner sacs being filled with a suitablefluid). Guided by a camera with illumination from a light source, theexpandable device reaches the site of polyp removal. Sporadic cleaningof the transparent sac covering the camera is performed using theirrigation instrument that protrudes through a portal adjacent to thecamera. Some blood is seen in the luminal wall of the colon at thetarget site and using the irrigation and suction instruments in adjacentportals, the blood is removed and the site is pictured for evaluation.The expandable device now moves in the reverse direction with its ownmobility assisted by peristaltic movement of the patient's colon and isextracted from the rectum by forceps through a speculum.

COMBO #12 (from above) would be useful, for example, in a clinicalsituation involving an inflammatory disease and an ulceration on thewall of an ovary. Here, incisions or flexible scopes involving tissuetrauma and manipulation could be relative contraindications. Thisexpandable device, being soft and compressible, can be inserted byvaginal speculum up to the cervix from where it moves into the uterusand through a fallopian tube that has an ulceration. A special glue toapply on the ovary is available, but is too viscous for transportthrough the supply port of a flexible endoscope which lacks enough portsfor one forceps to hold the capsule of glue which will be squeezed ontothe ovary, another to dissect surrounding adhesions (scar tissue) andanother to grasp the ovary and pull it away from the adhesions, notcounting camera and light source.

The arrangement of sacs and movable railed instruments allows for aninner sac of the expandable device to contain a squeezable capsule withthe glue. Once the main (outer) expandable device sac reaches thefimbrial opening, the inner sac moves out through a port (1) in thefirst sac wall toward the affected ovary. A camera is attached to theforward pole of the main expandable device sac.

Next, a blunt dissection instrument is moved by motor-on-rail mechanismadjacent to port (1) of the second sac and is used to dissect adhesionsaway from the ovary wall, after which it is withdrawn and the capsule,held by a forceps-like applicator instrument, is moved by motor-on-railmechanism through a port (2) in the second sac adjacent to port (1) ofthe second sac. The applicator with capsule now outside port (2) of thesecond sac squeezes glue onto a segment of the ovary adjacent to thefallopian tube fimbria, after which it withdraws into the second sacthrough port (2).

A forceps instrument is then advanced through this same port (2) tobring the ovary away from the adhesions and closer to the fallopianfimbria. A second forceps instrument advances through port (1) to holdthe fimbrial wall against the ovary while the glue sets (after thecapsule applicator is withdrawn). After instruments are withdrawnthrough the ports, the expandable device moves in the opposite directionuntil it is withdrawn by forceps via a vaginal speculum.

In one embodiment, the device comprises a plurality of d/t instruments.Such a device can perform a plurality of functions or processes, forexample, as required for a given medical procedure. Optionally, thedevice is configured to perform one of the following procedures,resection or partial resection, ablation, prostatectomy, coronary arterybypass; cutting away diseased tissue from sensitive parts of the bodysuch as blood vessels, nerves, or important body organs or structures;gallbladder removal; hip replacement; hysterectomy; kidney removal;kidney transplantation; mitral valve repair; pyeloplasty (surgery tocorrect ureteropelvic junction obstruction); pyloroplasty; tuballigation; removal of adhesions between organs and body structures;mucosal resection in lumens of various organs (e.g. in the sinuscavities); drainage of blood or abscess material from a variety of bodytissues (e.g. the dura of the brain, the pleural space around thelungs); ligament repair; spinal disc repair; spinal ligament repair;spinal bone resection and repair; aneurysm repair; polypectomy. With theteachings provided herein, the skilled artisan will readily appreciatewhich tools are useful for incorporation into an expandable device toperform such procedures. In one embodiment, all of the tools areprovided by the expandable device. In another embodiment, the procedurescan be performed in cooperation with manual operative means and othermanually operated instruments and devices and the expandable device onlycomprise some fo the required tools.

Movement

An expandable device of the present invention can be moved in anymanner. In one embodiment, the expandable device as a whole istransported. In one embodiment, segments or portions of the expandabledevice is moved.

In one embodiment, the expandable devices is manually transported, forexample, inserted into patient using a hand-operated instrument such asforceps. In such an embodiment, the expandable device is placed in thebody cavity and then expanded, for example, to create a stabile workenvironment and/or organ retraction.

In one embodiment, the expandable device comprises a motorized means formovement (or ‘means for global movement’ of the expandable device).Optionally, the motorized means for movement is any of: an luminalmotorized device tethered to a sac wall, a propeller (e.g. as detailedin U.S. Pat. No. 6,240,312), a linear actuator (e.g. pneumatic actuator,e.g. as detailed in U.S. Pat. No. 6,648,814), serially arrangedinflatable chambers (e.g. as detailed in US 2010/0022947), an bracing(e.g. inflatable) member coupled with a linear actuator (e.g. asdetailed in U.S. Pat. No. 5,337,732), a variable length extendingsegment (e.g. as detailed in U.S. Pat. No. 5,906,591), a pneumaticvacuum (e.g. e.g. as detailed in U.S. Pat. No. 5,906,591), a memoryshape actuator (e.g. as detailed in U.S. Pat. No. 7,655,001), motorizedwheels (e.g. as detailed in U.S. Pat. No. 7,126,303), walking legs (e.g.as detailed in WO2010/044053), magnetic locomotion (e.g. as detailed inUS20070265496; EP1591057, US20070265496, or WO2005122866), a guide trackand a drive mechanism for movement along the track (e.g. as detailed inWO2005/070310), or tractor treads (e.g. as detailed in U.S. Pat. No.6,240,312).

In one embodiment, the motorized means for movement (or ‘means forglobal movement’ of the expandable device) comprises a motorized devicetethered to the wall of a sac (‘tethered motorcar’), for example, asdetailed in Example 2, Example 3, and Example 13. Optionally, themotorized device is in the lumen of a sac of the expandable device.Optionally, the motorized device is a railed device (although non-railedmicrorobots can also be used to move a sac wall by tethering).Optionally, the motorized device is configured for inchworm movement(e.g. electromagnetic inchworm movement). Optionally, the expandabledevice comprise tethered motorcars configured to provide global movementof the device (i.e. the device as a whole), to spread the device out, orprovide segmental movement (i.e. bending, articulation, or otherlocalized movement of the sac wall), e.g as detailed in Example 13.Optionally, the tethered motorcar is reversibly tethered to a sac wall(e.g. by retractable pylon). If the tethered motorcar is a raileddevice, the rail can be unfixed from the wall, reversible fixed to thewall, or fixed to the wall at a location remote from the tetheredsegment.

In addition, the means for global movement of the expandable device canbe any means for moving robots or microrobots (e.g. as describedherein).

Methods

In one embodiment, an expandable device of the present invention is usedin a medical procedure requiring access to a body cavity, for example,to treat or diagnose a target site in or near the body cavity.

In one embodiment, the device is positioned and operated within a bodycavity of a patient. Optionally, the device is inserted into the patientthrough a natural orifice. Optionally, the device is inserted through anincision. Optionally, the devices is first inserted into a first bodycavity through a natural orifice and then inserted into a second bodycavity through an incision made in the first body cavity, for example,as in a NOTES procedure.

For example, a small incision is made and the device is inserted throughthe incision in its collapsed sate. The device can then be expanded, forexample, to provide space within the cavity of a patient and varioustools (e.g. housed by the device) are operated within the cavity toperform a medical procedures, including, for example, any proceduredescribed herein or described in any publication cited herein.

In one embodiment, a device of the present invention is used as or usedwith a natural orifice translumenal endoscopic surgical device, such asa NOTES device.

The devices of the present invention can be used to perform procedures(e.g. NOTES procedures) that, until now, required the most skillfulhands.

Procedure that can be performed with a present device, include, forexample, laparoscopic reflux surgery, cholecystectomy, appendectomy,adrenalectomy, obesity surgery, and treatment of linguinal hernia.

In one embodiment, the expandable device is used in combination withother devices such as a flex endoscope.

Examplary medical procedures that can be performed by an expandabledevice of the invention include: resection or partial resection,ablation, prostatectomy, coronary artery bypass; cutting away diseasedtissue from sensitive parts of the body such as blood vessels, nerves,or important body organs or structures; gallbladder removal; hipreplacement; hysterectomy; kidney removal; kidney transplantation;mitral valve repair; pyeloplasty (surgery to correct ureteropelvicjunction obstruction); pyloroplasty; tubal ligation; removal ofadhesions between organs and body structures; mucosal resection inlumens of various organs (e.g. in the sinus cavities); drainage of bloodor abscess material from a variety of body tissues (e.g. the dura of thebrain, the pleural space around the lungs); ligament repair; spinal discrepair; spinal ligament repair; spinal bone resection and repair;aneurysm repair; polypectomy.

The invention also contemplates the use of the present devices outsideof the medical field, for example, in search and rescue operations incollapsed buildings where rigid instruments cannot maneuver throughtight spaces and in which a present expandable device (e.g. possessingmalleability and containing viscous fluids) can spread more easily intocrevices or in diagnosis, maintenance and repair of tubular conduits asin plumbing pipes. As another example, an expandable device can beconfigured as a as toy, e.g. that is stimulating to the imagination andhelps teach biological systems, robotics, materials science and otherscientific concepts in an enjoyable manner

Superior Properties:

Among other advantages, examplary devices of the present inventionprovide one or more of the following superior properties:

-   -   1. Safe access to a body cavity    -   2. Safe and stable transport of instruments to the body cavity    -   3. Excellent visualization and illumination to decrease        disorientation    -   4. Superior suction/irrigation in a cavity    -   5. Superior maneuverability and triangulation of instruments.    -   6. Performs operations with smaller incisions    -   7. Expands a lumen or cavity without having to inject air into        body cavity, which would normally have to be absorbed and can        result in metabolic effects and exert pressure on body        structures such as blood vessels.    -   8. Provides continuity between the device and a cavity wall        having a target site

Safe access to a body cavity is facilitated, for example, in thoseinstances in which one body cavity (e.g. having a natural orifice; orthe female reproductive organs including the fallopian tubes or otherlumens) is used to allow access to another body cavity (e.g. the pelvicand abdominal cavities), for example, as in a NOTES procedure. Whileflexible endoscopes can be used to gain access to the abdominal cavitywithout need for incisions in the patient's body, the endoscopes havelimited functional capabilities based on inherent elongated design ofendoscopes and based on the number of portals through which tools can bemaneuvered simultaneously; whereas the expandable devices of theinvention can be configured to have any number of ports which serve toallow instrument access to the target site.

Safe and stable transport of instruments to the body cavity isfacilitated by a number of optional features of expandable devices ofthe invention. For example, the expandable device can provide a cushionfor tools housed therein. Further, the expandable device can comprise aplurality of compartments (e.g. different inner sacs) to separate thetools from each other and from the patient's body lumens in transit to atarget site. As such, the expandable device can provide not only anenvelope to maintain the instrument clean and sterile in a separate sacor chamber within a sac, but it can provide cushioning in the form ofsurrounding semi-viscous fluids and sacs that jostle each other whencompressed and can slide past each other absorbing the compressiveforces that the body exerts while in transit to the target location forthe desired procedures. Additionally or alternatively, examplaryexpandable devices can have fragmented or folded tools (e.g. robots)that are provided in a collapsed configuration in route to the targetsite, thereby minimizing trauma to a body lumen. Once at the targetsite, the tools can be configured to function as needed (e.g. assemblyof fragmented tools or unfolding of folded tools) because examplaryexpandable devices provide a housing and assembling means (e.g.cooperating rails or pull strings) for the tools. An examplary robotdevice also provides a work environment upon expansion that can be used,for example, to service a tool before, during or after the operativeprocedure if needed.

Excellent visualization and illumination is provided, for example, byexpandable devices comprising one or more light sources and cameraswhich are either embedded in the sac walls, carried on railed devicesinside transparent sac walls, or otherwise provided in the expandablesac. The expandable device can have multiple cameras to provide morethan one or two points of view and allow, for example, for markers to beplaced in the surrounding sac walls to serve as orientation markers inaddition to micro-gyroscopes (e.g. known MEMS devices) to giveadditional feedback to the operating team members. An examplaryexpandable device can not only comprise and transport multiple sensorydevices into the vicinity of the target location, but provides (e.g.upon expansion) for a stable platform/work environment to maneuver thesensors into position and/improve orientation and visualization.

Superior suction and irrigation in a body cavity or space isindependently or collectively accomplished by a number of features ofexamplary expandable devices. For example, an expandable device cancomprise suction and/or irrigation tools that can accurately be placed.Further, these tools can be attached to different “appendages” to extendthe suction and/or irrigation tools outward in multiple directions tosuction fluid or debris resulting from operative procedures. The“appendages” are, for example, evaginating sacs (e.g. inner sacsevaginating through ports in the outer sac), robotic arms (e.g.telescoping arms), or segments of the outer sac wall that can extend,e.g. by expansion of the sac wall (e.g. as in a malleable sac wall).These appendages can be used, e.g. for reaching and encompassing spacesin between body organs or tissues. In addition, multiple cameras andsensing devices embedded in the wall of the sacs or in the luminalcavity of the sacs can be provided detect the material to be suctioned.In addition, the incorporation of ports in an expandable sac wall can beused to release and retract sponges, aspiration tubes, or irrigationtools. Alternatively, an outer sac wall can contain a segment ofabsorbent material released from an invagination of the sac wall asformed, for instance, inside the space of an invaginated pleated segmentof an outer sac wall.

Superior irrigation is accomplished, for instance, via one or more fluidexpelling devices carried on a rail and protruding through ports in sacwalls which can be maneuvered, e.g., with a change in shape of a sacwall or the movement of inner sacs themselves through portals in theouter sac wall of the expandable device.

Superior maneuverability and triangulation of instruments is provided,for example, by the ability to deploy a stable work environment orplatform about which tools can move. For example, the expandable devicecan provide a framework or multiple frameworks on which moving tools arestabilized and, if desired, a base from which tools can exert the neededforce against the target tissue. This can be used, for example, toaccomplish any one of numerous operative procedures such as spreadingapart or stabilizing tissue while it is being treated (e.g. sewn, cutetc). The expandable device also provides for precision movement of thed/t tools, for example, allowing only its desired moving parts (e.g.tissue-contacting members) to move in the manner in which it has beenconfigured to perform a desired functional task. Another feature ofexamplary expandable devices that provides a desired maneuverability andtriangulation is the use of expandable frameworks (e.g. “T” framework).Multiple, appropriately sized tools can be brought into close proximityto the target tissue allowing for simultaneous operations, e.g.retraction of tissue parts, clamping, cutting, irrigation and suctioningof fluids followed by clipping, suturing, cautery, suctioning ofsurgical smoke, cleaning the operative field and nearby cameras or toolsusing a water stream, irrigation of resultant fluids and so forth duringcommonly performed operative functions required in gall bladder removal,polypectomy, tubal ligation and numerous surgical procedures. Otherexamples of operative procedures in which an expandable device canprovide superior maneuverability and triangularion are described in theliterature for instance in Abe, N et al., (Single incision multi-portlaparoendoscopic surgery . . .http://www.springerlink.com/content/h81h3133v808q6jv/fulltext.pdft).This article delineates how one flexible, multi port endoscopic toolperforms a segment of gall bladder removal surgery. The expandabledevice, in this respect, can have multiple ports akin to the 3 or 4ports available in the endoscopic tool. Whereas the endoscopic tool hasa much smaller limit in number of port based on the diameter of theendoscope, the present expandable device can have many more ports thatcan be brought to bear on the performance of needed functions. Further,examplary expandable devices of the present invention are automated orsemi-automated and do not require highly skilled hands to maneuvertools, as is required for endoscope-based procedures.

Superior maneuverability and triangulation is also imparted, forexample, in a device comprising a segmented or localized embeddedinflatable conduit and/or inflatable rail network which can be engorgedwith a suitable substance (e.g. fluid) which gives segmental rigidity,hence stability, to those local segments. At the same time, this allowsfor movement (e.g. articulation) in the sac wall that is between therigid rail or conduit segment. Added articulation is one means ofproviding degrees of freedom to the entire sac, in addition to thearticulations provided by the internal framework, when deployed. Hencethe presence of inflatable conduits and/or rails can impart bothsegmental rigidity and articulation, enabling additional control foroperative procedures.

Examplary expandable devices of the present invention can performoperations with smaller incisions, having the capacity of taking aminimal (collapsed) shape during entry through an incision in bodytissues, e.g. the skin of a patient. This is achieved by, for example,the malleable or foldable nature of the sac walls and the capacity toempty a sac (e.g. through an access tube) of many or even all of itshoused tools apart from structures (both pliable and semi-pliable) thatare embedded in the sac wall(s). Numerous devices (e.g. tools ormicrorobots) can be introduced into the interior of the sac(s) (e.g. viaaccess tube) after the initial sac has made entry into the desired bodyspace (cavity, lumen or potential cavity). The devices can be introducedthrough the incisional space single file as fully assembled, folded, orfragmented tools.

Movement inside the body of a patient is also rendered easier by thecapacity to maintain a compressed or thin profile while in the body,when moving or when immobile.

Examplary expandable devices of the present invention can expand a lumenor cavity without having to inject air into body cavity, which wouldnormally have to be absorbed and can result in metabolic effects andexert pressure on body structures such as blood vessels. An examplaryexpandable device has the capacity to expand the sac walls in multipledirections, simultaneously to allow instruments or tools appropriateaccess to the body organs and tissues. This capacity can be achieved,for example, with more than one co-existing means, i.e. built-inredundancy. For instance, the means to expand a sac wall include:introduction and removal of fluids (e.g. gas, liquid, or semi-solid(g/l/s)) substances into multiple sacs in various quantities so as toachieve the desired expansion. Expansion can occur via introduction offluids into any of multiple sacs in appropriately placed locations asalready described. Expansion of sac wall(s) can also be achieved byintroduction of the fluids into imbedded inner sacs or expandableconduits in the wall of an outer sac. Through the use of inner sacframeworks, malleable sacs, and/or tethered motorcars, a sac wall can bethus shaped to be contiguous to a body organ or tissue in its entirety(e.g. surrounding it) or in a segment of the organ or tissue, andthereby minimize or eliminate the need to transport a robotic device ortool far outside of the expandable device for the needed access to thetissue.

Examplary expandable devices provide continuity between the device and acavity wall having a target site. For example, the use of a malleablesac can be used to deform a sac wall such that it is continuouslypositioned (e.g. contoured) against a cavity wall (e.g. a curved orirregularly shaped wall). Additionally or alternatively, expansion ofthe sac can occur in a segmented or localized manner, for example, inexpandable devices comprising malleable sacs and/or tethered motorcars.Additionally or alternatively, segmental contiguity of the luminalcontents of a sac(s) with an area of tissue can be achieved, forinstance, by maneuvering (through a port in the outer sac wall) a secondinner sac, which protrudes to the exterior surface of the outer sacexpandable device, and is thus brought into contiguity with an area oftissue to which a substance is to be delivered that is contained in theinner sac). An adhesive (e.g. coated elastomer as described by Mahdaviet al) introduced to the exterior aspect of the portal of thesecond/inner sac touching the target tissue provides a temporary seal tominimize or prevent leakage of the contents of the second/inner sac asthey are brought into contact with the target tissue (by being sprayed,squeezed or otherwise released from a containing capsule). Hence, adesired material (e.g. therapeutic) is segregated from contact with anybody tissues apart from the target tissue and after release to thetarget tissue leakage into the body (tissues or cavities) is likewiseminimized or prevented. Examples of procedures that would benefit fromthis capability include: delivery of small amounts of expensiveantibodies which should not be wasted, alpha emitting radioactivesubstances which should not be brought near healthy tissue, biologicalagents (e.g. living cells, bacteria, animals, worms, leaches, worms) orplant substances which can perform specific therapeutic functions todiseased tissue but should not be exposed to healthy tissue. In additionto delivery of special substances to a given tissue, the combination ofthese just described structural features allow for a contiguously placedport (e.g. sealed temporarily with adhesive) to enable more encapsulatedevacuation of diseased tissue (e.g. cancerous cells) without allowingfor contamination of any other body space or tissue. Suction tools onrobotic devices can be maneuvered to this portal using for example themotorized railed devices. Thus, the diseased tissue is suctioned into anencapsulated space, such as an empty canister transported on a rail orelse an inner sac.

The advantages of the invention can be combined with the complementaryuse of other surgical tools and methods. For example, in one embodiment,the a surgeon performs some activities with their hands, and a device ofthe present invention is used to provide expansion of the cavity (e.g.abdomen), illumination with light sources, visualization with imagingdevices, fluid absorbtion/suction with a suction device, and irrigationwith an irrigation device. Without the use of a device of the presentinvention, such a method would otherwise require a large incision in theabdominal cavity or multiple incisions.

The use of multilayer sacs arrangements allows compartmentalization of avariety of complementary functions and capabilities into one device. Forexample, the sacs can serve to contain and separate different processesif they should not be in contact with each other. The sacs can laterexpel their contents into a common area within or outside the expandabledevice.

The use of motors situated along different parts of the outer or innersacs allows a variety of functions such as moving the sac or differentportions of the sac in multiple directions and multiple planes in unisonor at different intervals to allow shapes to be formed as needed andmovements as need.

The use of malleable sacs allows compression or folding when the sacsare going through a tight space (e.g. incision into an inside the bodyor between organs in the abdominal or thoractic cavity).

The use of malleable sacs allows the external or internal sacs alongwith their internal contents and attachments to become compressed and tobecome filled with varying types and amounts of fluids and canfacilitate various types of movement, including sliding squeezing,engorgement, and taking various shapes as required for the applicationin the body lumens and cavities. For instance, the use of malleable sacsprovides capacity of the external or internal sacs to sustain physicalforces that a) squeeze or pressed together, or against adjacent sacs orbody structures (e.g. in sliding against lumen walls, body cavities, orinternal organs, bending around lumen walls, body cavities, and inbetween internal organs); b) extend the sacs in the desired directions,c) configure the sacs in desired shapes. Preconfigured, contiguousexpandable units of any shape can be selectively expanded to formdesired shapes for specific purposes by having fluidic contents withinone of the internal sacs flow into preformed or created spaces withinanother adjoining sac to create a space within the abdominal cavity. Forinstance, a rounded, smooth contoured, and deformable sac can beconfigured to much more easily pass through lumens and cavities inbetween organs, and other passages of the body (e.g. sinuses). The useof liquids/gasses or semisolids can also give a shape to the expandabledevice which could expand to allow lumens lined with smooth muscle tocontract around the sac and push it along one direction or another. Thisnaturally occurring process called peristalsis usually occurs in the GItract.

The use of malleable sacs provides, among other advantages, a contouringdevice configured to shape around an organ to take on its exteriorshape. This can be further facilitated by orchestrated movements ofoptional motorcars tethered to a sac wall (e.g. to impart bending).

Among many other superior properties, examplary expandable devices ofthe present invention aim to take advantage of various factors suchas: 1) the properties of materials that render malleability or viscosityto expandable sacs, 2) specific means to shape and move such sacs, and3) arranging sacs within each other to allow compartmentalization orseparation of diverse functions while also allowing intercommunicationamong the sacs as needed. As a result of the integration of theseexemplary factors, the platform device can perform procedures withremarkable cooperation of tools.

Shaping and mobility of the present device can be accomplished, e.g.through a network of tracks or rails coupled to movable componentsattached to the walls of the sacs, although other suitable means ofimparting movement and shape to the sacs using fluidics technology areavailable. Intercommunication between the lumens of the sacs and thebody cavity occurs via portals through which devices can move to othersacs or sacs themselves can move into other sacs or into the bodycavity.

Examplary superior functions offered by a present expandable deviceinclude one or more of: shaping within, around, or inbetween bodylumens, cavities and organs to bring diagnostic, therapeutic, and otherfunctional devices, including micro robots, into close proximity to thetarget tissue while also enabling the retraction, interaction, supply,servicing and transportation in and out of the body of these devicesalong with targeted organs, tissues or fluids.

The citations provided herein are hereby incorporated by reference forthe cited subject matter.

EXAMPLES Example 1 Electromagnetic Inchworm Motor

FIG. 7 depicts a railed device coupled to a rail 58. The railed devicecomprises an electromagnetic motor of the electromagnetic inchworm type.The railed device comprises a tool (camera) 56 mounted on a railcar 47.The inchworm motor comprises three railcars 46, 47, and 48, eachcomprising an electromagnet having poles, 49-50, 51-52, and 53-54,respectively. Each of the electromagnets is independently operable tocontrol the charge at each pole and move the railed device byelectromagnetic (attraction/repulsion) forces. Although the distancebetween railcars can be controlled by precise operation of theelectromagnets, a distance limiter such as cable 57 is optionallyprovided to restrain the electromagnets from moving out of range of eachother (for electromagnetic interaction). The electromagnets can beoperated in any manner that imparts movement of the railed device aboutthe rail 58.

As an alternative to providing each railcar with two poles, the railcarscan have a single pole. As another example, the lead car 46 and trailcar 48 can each contain a single pole to interact with the intermediatecar 47, which can contain two poles 51 and 52 to interact with the leadcar and trail car, respectively.

Optionally, the electromagnetic inchworm motor is provided as a railedor non railed device and need not carry any particular device (such asthe depicted camera). The electromagnetic cars will function as long asthe electromagnets are arranged substantially collinearly. The“collinear” arrangement can be strictly collinear (head to toe) orfunctionally collinear, i.e. the electromagnets are arranged to interactwith each other by repulsion and attraction.

Surprisingly, such an electromagnetic inchworm motor can translocate adevice, even without means to transiently stabilize or break a rail car(or car) such as a friction break or a clamp or other breaking device.

Example 2 Movement of an Electromagnetic Inchworm Motor

A railed device comprising an electromagnetic motor (e.g. as in Example1 and FIG. 7) can be moved in an inchworm fashion by step-wise operationof electromagnets, as detailed in FIG. 6. The railed device compriseselectromagnet railcars 46, 47, and 48, each comprising poles, 49-50,51-52, and 53-54, respectively. The railed device optionally comprises adistance limiter such as membrane 55.

The railed device motor is configured to move the railcars in thefollowing states:

-   -   1. Idle state: the electromagnets are charged such that no cars        move    -   2. Lead car advance state: the lead car 46 advances by repulsion        from intermediate car 47;    -   3. Intermediate car advance state: the intermediate car 47        advances by attraction to lead car 49 and/or repulsion from        trail car 48.    -   4. Trail car advance state: the trail 48 advances by attraction        to intermediate car 47.

The railed device can be moved in the opposite direction by reversingthe steps. Each moving step or state is imparted by selecting anappropriate combination of charges on the electromagnet railcars thatprovides the desired state. Although numerous charge combinations existthat can provide each moving step or state, FIG. 6a through FIG. 6gdepict one method for moving the railed device in an inchworm manner,wherein each step requires the modulation (changing) of only a singlecar's electromagnet(s). This is achieved by providing a railed devicewith rail car weights as follows: the weight of the intermediate car isless than the lead car and less than the trail car; the weight of thelead car is less than the combined weight of the intermediate and trailcar; and the weight of the trail car is less than the combined weight ofthe intermediate and lead car (where “weight” is the object's resistanceto motion).

FIG. 6a depicts the idle state in which poles 50 and 53 are negative andintermediate car 47 is neutral or positive.

To advance the intermediate car, as depicted in FIG. 6b , theelectromagnet(s) on the intermediate car 47 is modulated to providefront pole 51 with a positive charge (attracting to lead car 46) andrear pole 52 with a negative charge (repelling from trail car 48).Intermediate car 47 weighs less than lead car 46 and trail car 48.Accordingly, the electromagnetic forces move the intermediate car ratherthan the lead or trail car.

To advance the trail car, as depicted in FIG. 6c and FIG. 6d , theelectromagnet(s) on the trail car 48 is modulated to provide front pole53 with a positive charge (attracting to intermediate car 47). Trail car48 weighs less than lead car 46 and intermediate car 47 combined.Accordingly, the electromagnetic forces move the trail car 48 ratherthan the lead or intermediate car.

To advance the lead car, as depicted in FIG. 6e , the electromagnet(s)on the lead car 46 is modulated to provide rear pole 50 with a positivecharge (repelling from intermediate car 47). Lead car 46 weighs lessthan intermediate car 47 and trail car 48 combined. Accordingly, theelectromagnetic forces move the lead car 46 rather than the trail orintermediate car.

To advance the intermediate car, as depicted in FIG. 6f , theelectromagnet(s) on the intermediate car 47 is modulated to providefront pole 51 with a negative charge (attracting to lead car 46) andrear pole 52 with a positive charge (repelling from trail car 48).Intermediate car 47 weighs less than lead car 46 and trail car 48.Accordingly, the electromagnetic forces move the intermediate car ratherthan the lead or trail car.

To advance the trail car, as depicted in FIG. 6g , the electromagnet(s)on the trail car 48 is modulated to provide front pole 53 with anegative charge (attracting to intermediate car 47). Trail car 48 weighsless than lead car 46 and intermediate car 47 combined. Accordingly, theelectromagnetic forces move the trail car 48 rather than the lead orintermediate car.

Optionally, the electromagnetic inchworm motor is provided as a railedor non railed device and is useful even outside (without) expandabledevices of the invention. The electromagnetic cars will function as longas the electromagnets are arranged substantially collinearly. The“collinear” arrangement can be strictly collinear (head to toe) orfunctionally collinear, i.e. the electromagnets are arranged to interactwith each other by repulsion and attraction.

Surprisingly, such an electromagnetic inchworm motor can translocate adevice, even without means to transiently stabilize or break a rail car(or car) such as a friction break or a clamp or other breaking device.

Example 3 Sac with Railed Device

FIG. 1 depicts an embodiment of the present invention. The devicecomprises an expandable sac 1 having a flexible access tube 2 forfilling the sac with a fluid, thereby expanding the sac. The access tubemay also be used for clearing or collapsing the sac. The devicecomprises one or more railed devices 3 which carry tools (e.g. robot orcamera) and/or are tethered or attached to portions of the sac wall formovement thereof.

The sac wall comprises one or more portions 5 which are malleable toprovide expandability of the sac at that portion 5. The entire sac wallcan be malleable and can also have various portions with differentmalleability to provide differential expandability. A one or more raileddevices (e.g. motorized railed devices) can be tethered to the sac wallto move (e.g. push or pull) the sac along an axis or along multiple axessimultaneously. Alternatively, a plurality of railed devices can betethered to the sac wall to pull the sac along multiple axes, forexample, simultaneously. In this example, the device can be configuredto spread itself out. By selecting a sac with an appropriate design andmalleability the tethered railed devices can be arranged and configuredto predominantly move the sac about one axis, thereby moving the entiredevice in one direction while also being able to spread out in otherdirections. With the appropriate selection of sac and railed devicearrangement, the device can also be configured to form different shapes,e.g. cavitations, encircling, or pincher-like movement, etc. in order toexecute desired functions.

In addition to using solid, gaseous, or semi-solid substances to achieveexpansion, the access tube configured and used to introduce/removedevices such as mini or micro robots pushed or suction with air or fluidor with a plunger type device.

Example 4 Multilayered Device with Ports

FIG. 2 depicts an expandable device of the invention. The devicecomprises an outer sac 6 having one or more malleable portions 13.Additionally, the entire sac can be malleable and/or can have portionswith different malleability to provide differential expansion. The outersac 6 comprises a port 14 (e.g. a valve) configured to provide afluid-tight enclosure when the port 14 is closed and allow access to theperiphery of the sac 6 when the port is open, for example, to allow atool housed by the sac 6 access to a target tissue in a body cavity.

The device further comprises intermediate sac 7 (an inner sac) in thelumen of outer sac 6. The intermediate sac 7 comprises a connection 18to access tube 17 for filling and/or clearing the sac 7 of a fluid toprovide expansion and/or collapsing to modulate the volume of thedevice. The device transitions from the collapsed state, as depicted inFIG. 2b , to the expanded state, as depicted in FIG. 2a , by filling theintermediate sac with a fluid. Like the outer sac 6, the intermediatesac 7 comprises a port 15 providing access to its periphery. Theintermediate sac 7 is useful, for example, to allowfluid/gas/liquid/solid or semi-solid substances to be received and/or toserve as a holding chamber for suctioned fluid or tissue from the body.

The device further comprises inner sacs 8, 9, and 10 in the lumen of theintermediate sac 7.

Inner sac 8 comprises a port which can be configured for transient orpermanent alignment with port 15 of intermediate sac 7, which can itselfbe configured to align with port 14 of outer sac 6. In thisconfiguration, a tool housed by inner sac 8 (not depicted in the figure)has access to the periphery of outer sac 6, for example, to contact atarget tissue in a body cavity.

Inner sacs 9 and 10 are connected by a connecting sac 11. Inner sac 9contains tools such as microrobots 12 for performing a desired function.This configuration provides, for example, expansion or expansivecapability if a tubular segment is not available or if a sealed chamberis needed, for example, if sac 7 is filled with a fluid which should notenter either of the adjoining sacs.

Sac 8 may contain, for example, something other than a robotic tool, forexample, a folded layer of artificial membrane that will be deliveredfor placement on a diseased body organ, e.g. a blood vessel wall. Sac 9can then be used, for example, to house the robot(s) that can be used toremove the membrane from sac 8. Although a robot and a delicate material(e.g. artificial membrane) can be housed in the same sac,compartmentalization of the two protects the delicate material, duringtransport through tight spaces in the body, wherein the robots couldotherwise pierce the delicate membrane. Further, the viscous fluid canbe filled in sacs 7 and 9 could to act as cushions protecting both themembrane and the robots from compressive forces and from contact witheach other.

Such a device with multiple inner sacs provides compartmentalization ofcomplementary processes/instruments. This is especially useful when theprocesses/instruments should be separated, i.e. not in direct contactwith each other. As one example, radioactive substances can require thata specified protective parameter be maintained at all times untildelivery into a target tissue. The availability of a separate sac whichcan be maintained at a specific volumetric configuration facilitatesthis requirement.

Example 5 Multilayer Sac with Railed Device

FIG. 3 depicts a device comprising an outer sac 19 having a rail 20mounted by rail support 28. FIG. 3a is a cross-sectional (front) viewwhile FIG. 3b is a perspective view (note that several parts are notdepicted in the perspective view). A railed device 21 (e.g. with motor)is coupled to the rail 20 by rail mount 29 and is tethered to the outersac 19 by tethers 22. In this configuration, the railed device 21 actsas a motor car, using the tethers 22 to moving the outer sac.

The device further comprises a first inner sac 23 comprising adiagnostic device (e.g. camera) or other instrument. The sac 23 canoptionally be attached to the outer sac (or other sac) by attachmentpoints 24. The sac can be filled with a gas or other fluid to impartvolume there to, for example, to stabilize the sac and diagnostic device(e.g. camera) as well as to protect the diagnostic device from contactwith the outer sac and/or body cavity.

The device further comprises one or more second inner sacs 25 and 26with access tubes (not shown) and can be filled with a gel or otherfluid to impart shape and volume to the device.

The device further comprises a third inner sac 27 having an access tube(not shown) and can be filled with a viscous (thick and/or cushioning)fluid or other fluid.

Among other advantages, filling with a fluid can provide cushioning ofthe railed device (or other components) from compression by bodystructures and from an instrument (or other tool) contained in sac 23and cushioning of the instrument from same (body structures and rail).In examplary expandable devices, as the sacs slide against each other,this facilitates squeezing of the entire platform through tight spaceswithout causing undue trauma against the adjacent body tissues ororgans. Through optional ports or valves (some of which can beconfigured with small openings even when in the opened position), notdepicted in this figure, very small amounts of viscous fluid (when thesacs are configured to contain such fluid) can be squeezed out when thesacs are compressed producing lubrication between the sacs, therebyfacilitating squeezing and spreading movement of the entire platform.These same fluids can make their way into the luminal space of the outersac 19 and into the body through similar ports in the wall of the outersac 19 serving as lubricant for the entire platform as it moves, whenthis is needed

Example 6 Multilayer Device with Framework

FIG. 4 depicts a device comprising an outer sac 30 and en expandableframework comprising a plurality of expandable sacs 31 connected byjunctions 32. The framework can be fluidly connected to a fluid pump byaccess tube 35.

In one embodiment, the junctions 32 are tubes connecting the sacs 31such that the sacs 31 are fluidly connected. Alternatively, theframework can be configured as a disassembled framework comprising aplurality of sacs 31 which comprise self-assembly elements to assembleat junctions 32.

In one embodiment, the device comprises means for expansion of the outersac at a junction 36 at a location remote to the framework (e.g. secondinner sac or another expander).

An “L” or a “T” shaped framework can be used, for example, to expand andprovide a working space (e.g. between two organs 33 and 34) while alsoproviding a stabilizing member (e.g. the top portion of the “T”), asdepicted in FIG. 4.

In one embodiment, the device comprises means for movement of an innersac through a port (port not depicted) in the outer sac 30 near thejuncture 36. The means for movement of an inner sac can be any of: arobot, an actuator, pneumatic device, or other means.

Example 7 Multilayered Device

FIG. 5 depicts a device comprising an outer sac 37 and an inner sac 38in the lumen of the outer sac 37. In the lumen of the inner sac 38 is arailed device comprising a camera 37 coupled to rail 40.

Parts 41, 42 and 43 are optional parts of the expandable device, suchrailed devices capable of traveling along the rail 40 which isconfigured (e.g. by expansion) to span the opposing luminal walls of theinner sac 38 e.g. in performing functions requiring contact with aconcentric surface of the luminal wall as the device and/or the platformadvance, such as in ultrasound scanning of the circumferential luminalwall of the intestines.

The space between the outer wall of inner sac 38 and the luminal wall ofouter sac 38 can be filled with a fluid (e.g. gas, liquid, or gel, forinstance gel used for ultrasound transducers functioning or cushioning).

The device is optionally inserted into the colon 45 and travels therethrough as it images the colon wall. The device can travel, for example,by muscle contraction (e.g. peristalsis, retro-peristalsis, orelectrical stimulation).

As depicted in FIG. 5b , the device can optionally comprise an inner sac59 configured to expand in the colon. This can be used for stabilizationor movement of the expandable device. For example, expansion of theinner sac can be used for anchoring one or more segments (portions) ofthe device against the walls of the lumen, a body cavity, or adjacentorgans in the body.

Example 8 Multilayer Device

FIG. 8a depicts an expandable device of the invention.

The device comprises an outer sac 105 (FIG. 8b ) and an inner sac (FIG.8c ) in the lumen of the outer sac 105. One or both sacs have theirlumen in fluid connection with an access tube. For example, outer sac105 can have its lumen in fluid connection with access tube 107 andinner sac 106 can have its lumen in fluid connection with access tube108

The outer sac 105 has a rail 109 mounted to its luminal wall and a port110 in proximity to the rail 109 such that a robot arm (robot not shown)can pass through the port 110 when coupled to the rail 109.Alternatively, the port 110 can be sized to allow a target tissue topass through and protrude into lumen of the outer sac 105 such that arail-mounted robot can interact with the tissue.

The device is optionally configured such that expansion of outer sac 105is imparted by filling inner sac 106 with a fluid through access tube107. The inner sac 106 can optionally be configured as a network ofsmaller sacs 111 fluidly connected by junctions 112.

The port 110 can optionally be configured as a valve such as aself-sealing valve. The self-sealing valve can be configured, forexample, as an elastic member having slits 126 that can open, allowing adevice (e.g. robot) to pass the valve and reseal upon retraction of thedevice back through the valve as depicted in FIG. 8 d.

Example 9 Multilayer Device

FIG. 9 depicts an expandable device comprising an outer sac which may beused in combination with of the depicted inner sacs. The devicecomprises an outer sac 113 and an inner sac 118, as depicted in FIG. 9c.

As depicted in FIG. 9a , a rail 114 is mounted to the luminal wall ofthe outer sac 113 and one or more d/t devices or other tools such ascamera 115 and robot 116 are coupled to the rail 114 as railed devices.The railed devices optionally comprise a motor such as a motor withthree electromagnetic rail cars 117. Although the d/t devices 115 and116 are shown as mounted on the motor railcars 117, these devices canalternatively be coupled to the rail on independent rail cars and pushedor pulled by the motor railcars.

As depicted in FIG. 9b , the inner sac 118 can comprise a plurality ofsmaller sacs 119 with lumens fluidly connected to access tube 121 andfluidly connected by junctions 120 (e.g. tubes) to provide an expandableframework. Optionally, the inner sac 118 is in the shape of an “L” or“T”, as depicted, for example, to create a working space between twoorgans while providing stabilization in a similar manner as described inExample 6. Optionally, the outer sac is malleable and configured toremain expanded upon deflation of inner sac 118.

As an alternative to the expandable framework of inner sac 118 depictedin FIG. 9b and FIG. 9c , the device can comprise inner sac 122 which isformed as a bilayer defining a thin lumen in fluid connection withaccess tube 123, as depicted in FIG. 9d . The inner sac 122 isconfigured with windows 124 through the bilayer such that inner sac 122can remain expanded while the railed device 115 moves along the rail, asdepicted in FIG. 9 e.

Example 10 Budding Segment

In one embodiment, an expandable device (e.g. multilayer device)comprises a segment configured for budding out, as depicted in FIG. 10.The sac (e.g. outer sac 113, as described in Example 9) comprises asegment 125 configured for budding out. The segment 125 can beconfigured for budding out by any manner. For example, the segment 125can be a malleable segment such as a segment made from a memory shapeplastic. Alternatively, if the sac is malleable as a whole then segment125 can be a thinner walled segment that provides greater flexibility.Alternatively, the segment 125 can be configured as a bundled segmentbound by a temporary clip.

The segment 125 can be induced to bud out, for example, by fluidpressure or by manipulation (e.g. pushing) with a robot.

Such a budding segment provides a superior working environment fortarget sites that are secluded in smaller cavities (e.g. diverticula) inthe walls of a larger cavity or other small openings that the entireexpandable device cannot fit within.

Example 11 Expandable Device

FIG. 12 depicts an expandable device of the present invention. FIG. 12adepicts the entire device while FIG. 12b through FIG. 12f depict zoomedviews of several optional components of the expandable device.

As a non-limiting example of a body cavity, the device is shown in thelumen of a sigmoid colon 61 (FIG. 12a ).

The device comprises:

-   -   a. an outer sac 62;    -   b. one or more ports 63, 64;    -   c. a rail 65;    -   d. one or more railed devices 70, 71, 72, 73, 74, 75, 76;    -   e. one or more inner sacs 77, 80, 81;    -   f. one or more robots 82, 87    -   g. one or more d/t tools 70, 75, 76, 79, and    -   h. an access tube 86;

The outer sac 62 is a malleable sac comprising at least one malleablesegment 90 that can expand and/or conform, e.g. into a smallerpassageway or cavity such as diverticulum 89. A railed diagnostic toolsuch as ultrasound device 70 can then be used to scan the diverticulumfor irregularities. As an addition or alterative to the diagnostic tool,a railed therapeutic tool such as ablation tool 71 can be used to treattissue at a target site within the diverticululm.

In addition or as an alternative to a malleable segment 90, a smallerpassageway or cavity such as diverticulum 88 can be expanded into by anevaginating portion 78 of an inner sac 77 that exits the outer sac 62through a port 64 (e.g. valve). The diverticulum 88 can be inspected ortreated by d/t tool 79 (e.g. ultrasound probe or ablation tool (e.g. RFablation tool)) that is housed by or attached to the inner sac 77. Innersac 77 can be filled with a fluid (e.g. viscous fluid) to impart volumeor expansion of inner sac 77 into diverticulum 88. Optionally, inner sac77 is a malleable sac.

In addition or as an alternative to malleable segment 90 or port 64 withinner sac 77, the device can comprise a port 63 (e.g. valve) sized toallow passage of a robotic tool such as a therapeutic tool 75 (e.g.snare) for treating a polyp 91 or other target tissue. If thetherapeutic tool 75 is a railed device, the port can be positioned inproximity to the rail. As depicted in FIG. 12a and FIG. 12e , theexpandable device optionally comprise light sources such as railed light101 (e.g. for illuminating the lumen of the sac 62) shown near the endof the rail 100 and/or a sac wall-embedded light 85 (e.g. forilluminating the target site). The expandable device can also comprise acamera such as railed camera 76 for visualization during the procedure.

The expandable device can optionally comprise an inner lumen 80 fortransporting robots 82 or other tools. The inner lumen 80 can be filledwith a cushioning fluid (e.g. gel, liquid, or gas) to protect the tools82 from the patient and vice-versa during transport. The tools 82 can bedirectly housed by the inner lumen 80 or can be in the lumen of a secondinner sac 81, for example, to separate the tools from the cushioningfluid. Although not illustrated, the inner sacs 80,81 can comprisevalves for transport of the tools 82 from the inner sacs when needed.

The expandable device can optionally comprise an expandable or buddingsegment 83, as depicted in FIG. 12a and FIG. 12c . Although the buddingsegment 83 can be configure in any manner (e.g. ductile segment, shapememory segment, etc), the segment is optionally configured as a loopedsegment 94. Before insertion into a patient, the looped segment 94 islooped and clipped using a clip 93, thereby reducing the surface area ofouter sac 62. When desired, the clip 93 can be released (e.g. by heat)to allow the looped segment to expand, as depicted in FIG. 12c . Such abudding segment can be used to, for example, provide more surface areain the wall, expand the wall to bud out, or to provide curvature in thewall.

The rail 65 can optionally be provided as a network of interconnectedrails 67, 68, 69. Additionally or alternatively, the rail 65 can beprovided as an inflatable rail, as depicted in FIG. 12 f. The inflatablerail is comprises a flexible conduit, the lumen of which can be filledwith a fluid to impart turgidity to the rail. For example, theinflatable rail can be filled from an access tube 104 through an accesstube connector 103. The inflatable rail allows the rail to bepreconfigured in a flexible manner such that the expandable device canbe easily transported in the patient. When movement of railed devices isneeded, the inflatable rail can then be inflated to turgidity to form afunctional rail system. If the rail is a network of rails, theinflatable rail can optionally be configured with a fork (branch)splitting an input rail 67 into output rails 68 and 69. A controlcircuit can optionally be provided to differentially fill variousbranches of the rail network to turgidity by diverting fluid from aninput rail 67 to one of the output rails 68 and 69. As depicted in FIG.12 d, an examplary control circuit is a fluidic amplifier 66 comprisingan input rail 67 (conduit) which flows into a feedback cavity 98 andthen forks into output rails (conduits) 68, 69. The flow of fluid frominput rail 67 is selectively diverted to either output rail 68,69 usingcontrol passages (fluid inputs) 96 and 97 in combination with flow vent99. An example of such a fluidic amplifier is described in furtherdetail U.S. Pat. No. 4,000,757 (Freeman).

The outer sac 62 optionally comprises traction members 83 such asprotrusions or pods with filaments extending thereof on the outer wallof the sac. Such traction members can aid in movement of the expandabledevice through the body cavity.

The expandable device optionally comprises a housekeeping robot such asrobot 87 that configures the expandable device as needed during aprocedure. For example, as depicted in FIG. 12a and FIG. 12b , a walkingrobot 87 or other robot (e.g. microrobot) can be configured to moveand/or connect certain components within the expandable device.Optionally, the expandable device comprise an access tube(s) 86 that canbe selectively coupled to one or more components within the expandabledevice such as inner sac 77 or an inflatable rail. As depicted in FIG.12b , the expandable device can comprise clips 88 or other attachmentdevices (e.g. magnet) for securing a component 92 (e.g. segment of anaccess tube 86 or tool) to a sac wall 62 until needed. When needed therobot 87 can retrieve the component 92 and move or couple the componentto perform a desired function.

Example 12 Pleated Sac

FIG. 13 depicts a pleated configuration in an expandable sac (note thatthe FIG. 13 depicts pleats for illustrative purposes only and does notshow an enclosed sac). The sac comprises a plurality of segments 129connected by pleats 130. The pleats 130 provide preformed fold linessuch that the sac can expand from a collapsed state, as depicted in FIG.13a to an expanded state, as depicted in FIG. 13b . The segments 129 canbe stiff segments or malleable segments. The pleats 130 are flexible andoptionally malleable. The segments 129 and the pleats 130 can be made ofthe same material, e.g. where the pleats 130 are thinner-walled than thesegments 129, or can be made from a different, more flexible materialthan the segments 129.

Example 13 Tethered Sac Wall

FIG. 14 depicts an expandable sac wall tethered to a motorized device(‘tethered motorcar’). As detailed herein, an expandable sac wall can betethered to a motorized device (e.g. railed device) for movement of thesac wall. The expandable sac can comprise sac wall segments 131, 132coupled to motorized devices such as railed devices 135, 136, 137, 141,142, and 143 by tethers 138, 139, 140, 144, 145, and 146 respectively.The railed devices can move along rails 133, 134 to move (push or pull)the tethered segments of the expandable sac. The rails 133, 134 areoptionally unattached (free) from the expandable sac wall or areattached to the sac wall at a location other than at segments 131, 132to allow movement of the railed devices and tethered segments about therails.

In one embodiment, a plurality of tethered motorized devices can be usedto impart a bend or curvature in the sac by spreading or condensing asegment of the wall.

For example, the motorized devices can be used to transition the sacfrom a natural state (FIG. 14a ) to a curved state (FIG. 14b ) by movingthe tethered wall segments on one wall closure to each other and/ormoving tethered wall segments another wall further apart.

In FIG. 14b , the motorized devices 135, 136, 137 on rail 133 (shown onthe left side) have been moved closure to each other, thereby impartinga curve to the left. The sac wall can be induced to curve right bymoving the motorized devices 141, 142, 143 on rail 134 (shown on rightside) closure to each other. Depending on the configuration of the wallsegment and location of tethering, a given wall can be induced to curveeither way upon moving the motorized devices closure to each other (orfurther apart). For example, FIG. 14c depicts sac walls that curvetowards the rail as the motorized devices are condensed. Such aconfiguration can mimic, for example, the manner in which a bicep muscleinduces an arm to articulate at the elbow.

Although curved bends are depicted in the figures, the expandable devicecan also be configured to articulate (as in a joint or hinge) if the twoor more motorized devices are tethered to more rigid segments connectedby a pleat.

Such bending or curvature is useful, for example, as the expandabledevice travels through a curved body cavity or lumen (e.g. colon) orcontours against a curved organ or other target site.

Another useful movement imparted by such a configuration is provided byrepeatedly alternating the curved wall (alternating between left andright bending) to provide a “wiggling” action of the expandable sac. Awiggling action can be used to gently maneuver burrow a sac into orthrough a small passageway or in between two organs.

In addition to imparting curvature, the motorized rail cars can be usedto move the expandable device globally (e.g. pulling rear segments ofthe expandable device forward and repeating) or to spread the expandabledevice out (e.g. pulling segments along a plurality of axessimultaneously).

Example 14 Fragmented Tool

FIG. 15 depicts a fragmented tool useful in an expandable device of theinvention. The tool comprises fragments 147, 148, and 149 threaded on apull string 151. The pull string 151 can be anchored to one of theterminal fragments 147, 149 comprises a hook, ball, or other member 152for coupling to one terminal fragment as the string is pulled throughthe other terminal fragment. For example, to assemble the fragments 147,148, 149, the terminal fragment 147 is stabilized (e.g. held in place)while the string 151 is pulled through the terminal fragment 147. As thestring 151 is pulled, it brings fragment 149 and 148 into contact withfragment 147. Once in the correct orientation, the fragments 147, 148,149 are coupled together to form a functional tool. For example, theends of each fragment can have clips or locking members that couple toeach other as the string is pulled to tension. The fragmented tool canbe, for example, a robot with a d/t instrument such as forceps 150.

A fragmented tool allows the tool to be provided in a collapsed and/ormore flexible configuration while it is transported to a target site ina body cavity.

Example 15 Method of Using an Expandable Device

An expandable device of the present invention is provided.

The device comprises an outer sac comprising:

-   -   a. a rail system comprising a rail and railed devices comprising        motors (motorized railed devices such as inchworm-type motors);    -   b. one or more light sources;    -   c. one or more valves to allow protrusion of devices (e.g. d/t        devices) outside the sac when needed but prevent backward reflux        into the lumen of the sac while when the device is        withdrawn/retracted back inside the sac;    -   d. a small camera attached to the inner wall at the distal end;    -   e. an access tube at the proximal end of the sac (used to        transport fluids and/or devices into or out of the sac); and    -   f. irregular small structures or other traction members (e.g.        protrusions) on the external wall of the sac to permit better        traction with the body cavity wall.

The expandable device further comprises a first inner sac in the lumenof the outer sac. Like the outer sac, the inner sac has a rail system,light sources, valves, and a camera.

In the inner of the first inner sac is a second inner sac, alsocomprising a rail system, light sources, valves, and a camera.

The outer and/or inner sacs can comprise d/t tools (e.g. robot tools)for performing desired functions.

Through the access tube, fluids and/or devices (e.g. robots) can beinjected and withdrawn from the sac. In this configuration, the accesstube is initially attached to the outer sac, for example, through areversible coupler; however, the inner sacs can comprise couplers forconnecting to the access tube. The inner sacs can couple to the accesstube by maneuvering into position (e.g. using railed devices tethered tothe wall of the respective sac allowing a segmental crawling motion ofany of the sacs). Additionally or alternatively, a robot (e.g. walkingrobot) can be used to couple/uncouple sacs from the access tube, e.g. asdetailed in Example 11.

The expandable device is inserted into the patient by pushing the devicethrough the rectum into the colon manually using a rectal speculum.During insertion, the expandable device is in a collapsed state. Thesacs are flexible (e.g. malleable) such that the can be folded, rolled,or otherwise collapsed such that the expandable device has a minimalcross section. Once inside the colon, any gases or other fluids neededto expand one or more sacs can be injected through the access which isto be connected to the appropriate sac(s). Expulsion of the expandabledevice can occur, for example, by normal defecation, but if needed canbe pulled out of the rectum manually.

D/t tools (e.g. robots or other tools) which are to function within theexpandable device can be folded within the sac(s) if they are smallenough or flexible enough to fit through the rectum while inside theexpandable device. For instance, the tools needed to function within asac (e.g. the second inner sac) can be placed into the correct sac whileit is still visible outside the rectum and then complete the pushing ofthe entire expandable device or configuration of sacs through therectum. However, the tools can also be inserted into the lumen of sacsthrough the access tube once the expandable device has been inserted. Inthis manner, the tools can be individually pushed through the rectum.

Once launched into the colon, the expandable device can move through thecolon by any means, for example, by motorized devices tethered to thewall of the outer sac and/or by retroperistalsis (e.g. usingelectrode-induced or muscle contraction or other induced contraction orby voluntary muscle contractions)

The first inner sac can be expanded to a desired volume with gas orother fluid to allow the colonic wall to contract around the entireexpandable device and propel it up the colon in retroperistalsis inaddition to the movement imparted to the expandable device by themotorized railed devices moving along the rail of the outermost sac. Inthis manner, the expandable device travels to the target location with acamera for visual guidance.

To perform a clinical procedure, once the expandable device arrives atthe target site, one or more tools are transported to the appropriatelocation within the expandable device. In one embodiment, a smallultrasound probe can be used to image the body cavity by localizing theprobe against a sac wall which is in contiguity with the colonic wall atthe target location. For example, the probe is initially coupled to arail on the luminal wall of the second inner sac and then is transportedalong the rail to the site of a lesion in the colon. The second innersac can also be configured for segmental movement of its wall tetheredto a railed device until the probe it is aligned closely to the targetlocation at the colonic wall. Hence, the ultrasound probe is nowadjacent to the target location separated by the three walls of thethree sacs. At this point, the ultrasound probe is activated and scansthe wall adjacent to the lesion to image the colonic wall. Dependingupon the interpretation of the ultrasound images which are transmittedby the probe through radio waves, the user of the expandable device candeploy a therapeutic tool (e.g. cryogenic ablation tool), for example,through the access tube, then positioning the therapeutic tool alongsidethe ultrasound probe at the target site. The therapeutic tool is thenactivated, for example, by releasing a premeasured liquid inside thetool which cools it down to a desired temperature thus decreasing thetemperature of the adjacent walls of the three sacs such that the lesionwhich touches the outer surface of the outermost sac becomes frozen andsloughs off

Alternately, if the device and method chosen to obliterate the lesionrequires direct contact with the lesion on the colonic wall (e.g.cutting tool, laser, or RF therapy), a different therapeutic tool can betransported to the periphery of the outer sac wall through ports in thesac wall. If the tool is housed in an inner sac (e.g. second inner sac),the ports in each of the sacs are aligned to allow passage of the toolfrom the inner sac to the periphery of the outer sac. The tool can bemaneuvered though the ports using, for example, using a telescoping arm(or other robotic arm) that extends through the aligned ports to thelesion at the periphery of the outer sac. After treating the lesion, therobotic arm is withdrawn through the three ports. The ports can beconfigured as self-sealing valves such that they close upon the robotarm retracting back through the ports.

We claim:
 1. An expandable device comprising: a. a first sac, wherein the first sac is expandable; b. a rail in the lumen of the first sac; and c. a railed device coupled to the rail for movement there on.
 2. The expandable device of claim 1, wherein the rail is mounted to the luminal wall of the first sac.
 3. The expandable device of claim 1, further comprising a motor for providing said movement of the railed device.
 4. The expandable device of claim 3, wherein the motor comprises at least one electromagnet.
 5. The expandable device of claim 4, wherein: a. the railed device comprises a plurality of railcars independently movable on the rail; b. the at least one electromagnet is on at least one of said railcars.
 6. The expandable device of claim 5, wherein the at least one electromagnet is plurality of electromagnets, each on an independent railcar.
 7. The expandable device of claim 6, wherein the plurality of railcars comprises three railcars, a lead railcar, an intermediate railcar, and a trail railcar, wherein: the weight of the intermediate railcar is less than the lead car and less than the trail railcar; the weight of the lead railcar is less than the combined weight of the intermediate railcar and trail railcar; and the weight of the trail railcar is less than the combined weight of the intermediate railcar and lead railcar.
 8. The expandable device of claim 1, further comprising sensors on the first sac.
 9. The expandable device of claim 1, further comprising an access tube in fluid connection with the first sac.
 10. The expandable device of claim 1, wherein the first sac is configured for expansion by fluid pressure.
 11. The expandable device of claim 1, wherein the railed device is tethered to the first sac, whereby the first sac or wall segments thereof can be moved by moving the railed device.
 12. The expandable device of claim 11, comprising a plurality of rails mounted to the first sac.
 13. The expandable device of claim 12, wherein the plurality of rails comprises at least two longitudinal rails positioned laterally with respect to each other.
 14. The expandable device of claim 12, wherein the plurality of rails comprises at least two longitudinal rails positioned longitudinally with respect to each other.
 15. The expandable device of claim 11, further comprising a motor for providing said movement of the railed device.
 16. The expandable device of claim 1, wherein the first sac is malleable.
 17. The expandable device of claim 16, wherein the first sac is transparent.
 18. The expandable device of claim 16, wherein the first sac comprises a plurality of wall segments with different malleability.
 19. The expandable device of claim 18, wherein the first sac comprises a thermoplastic resin, wherein the first sac is malleable at a physiologically acceptable temperature.
 20. The expandable device of claim 1, wherein the first sac comprises a port connecting the lumen of the first sac with the periphery of the first sac. 